fix(test): validate MCP descriptor source locations

abi/proto/v1/manifest.proto

@@ -156,6 +156,26 @@ message PluginManifest {
   // HTTP handler) and merges them into the site sitemap. Requires
   // has_http_handler.
   bool sitemap = 37;
+
+  // mcp_tools is the descriptor-derived MCP surface for the plugin's own
+  // unary ConnectRPC methods. The Go guest binding captures these during
+  // DESCRIBE from the compiled protobuf descriptors; plugin authors do not
+  // duplicate schemas or procedure metadata by hand. The host still checks
+  // every procedure against rbac_method_roles before advertising or invoking
+  // it, so descriptor metadata cannot widen the plugin's authorization map.
+  repeated MCPToolDescriptor mcp_tools = 38;
+}
+
+// MCPToolDescriptor is one unary ConnectRPC method prepared for the host MCP
+// catalogue. Procedure, service, method, documentation, and the request JSON
+// schema are all derived from protobuf reflection during DESCRIBE.
+message MCPToolDescriptor {
+  string procedure = 1;
+  string service_full_name = 2;
+  string method_name = 3;
+  string description = 4;
+  string documentation = 5;
+  bytes input_schema_json = 6;
 }
 
 // PublicRoute is one site-root path claim (see PluginManifest.public_routes).

abi/v1/manifest.pb.go

@@ -149,7 +149,14 @@ type PluginManifest struct {
 	// entries from the plugin's well-known sitemap endpoint (served by its
 	// HTTP handler) and merges them into the site sitemap. Requires
 	// has_http_handler.
-	Sitemap       bool `protobuf:"varint,37,opt,name=sitemap,proto3" json:"sitemap,omitempty"`
+	Sitemap bool `protobuf:"varint,37,opt,name=sitemap,proto3" json:"sitemap,omitempty"`
+	// mcp_tools is the descriptor-derived MCP surface for the plugin's own
+	// unary ConnectRPC methods. The Go guest binding captures these during
+	// DESCRIBE from the compiled protobuf descriptors; plugin authors do not
+	// duplicate schemas or procedure metadata by hand. The host still checks
+	// every procedure against rbac_method_roles before advertising or invoking
+	// it, so descriptor metadata cannot widen the plugin's authorization map.
+	McpTools      []*MCPToolDescriptor `protobuf:"bytes,38,rep,name=mcp_tools,json=mcpTools,proto3" json:"mcp_tools,omitempty"`
 	unknownFields protoimpl.UnknownFields
 	sizeCache     protoimpl.SizeCache
 }
@@ -443,6 +450,100 @@ func (x *PluginManifest) GetSitemap() bool {
 	return false
 }
 
+func (x *PluginManifest) GetMcpTools() []*MCPToolDescriptor {
+	if x != nil {
+		return x.McpTools
+	}
+	return nil
+}
+
+// MCPToolDescriptor is one unary ConnectRPC method prepared for the host MCP
+// catalogue. Procedure, service, method, documentation, and the request JSON
+// schema are all derived from protobuf reflection during DESCRIBE.
+type MCPToolDescriptor struct {
+	state           protoimpl.MessageState `protogen:"open.v1"`
+	Procedure       string                 `protobuf:"bytes,1,opt,name=procedure,proto3" json:"procedure,omitempty"`
+	ServiceFullName string                 `protobuf:"bytes,2,opt,name=service_full_name,json=serviceFullName,proto3" json:"service_full_name,omitempty"`
+	MethodName      string                 `protobuf:"bytes,3,opt,name=method_name,json=methodName,proto3" json:"method_name,omitempty"`
+	Description     string                 `protobuf:"bytes,4,opt,name=description,proto3" json:"description,omitempty"`
+	Documentation   string                 `protobuf:"bytes,5,opt,name=documentation,proto3" json:"documentation,omitempty"`
+	InputSchemaJson []byte                 `protobuf:"bytes,6,opt,name=input_schema_json,json=inputSchemaJson,proto3" json:"input_schema_json,omitempty"`
+	unknownFields   protoimpl.UnknownFields
+	sizeCache       protoimpl.SizeCache
+}
+
+func (x *MCPToolDescriptor) Reset() {
+	*x = MCPToolDescriptor{}
+	mi := &file_v1_manifest_proto_msgTypes[1]
+	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+	ms.StoreMessageInfo(mi)
+}
+
+func (x *MCPToolDescriptor) String() string {
+	return protoimpl.X.MessageStringOf(x)
+}
+
+func (*MCPToolDescriptor) ProtoMessage() {}
+
+func (x *MCPToolDescriptor) ProtoReflect() protoreflect.Message {
+	mi := &file_v1_manifest_proto_msgTypes[1]
+	if x != nil {
+		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
+		if ms.LoadMessageInfo() == nil {
+			ms.StoreMessageInfo(mi)
+		}
+		return ms
+	}
+	return mi.MessageOf(x)
+}
+
+// Deprecated: Use MCPToolDescriptor.ProtoReflect.Descriptor instead.
+func (*MCPToolDescriptor) Descriptor() ([]byte, []int) {
+	return file_v1_manifest_proto_rawDescGZIP(), []int{1}
+}
+
+func (x *MCPToolDescriptor) GetProcedure() string {
+	if x != nil {
+		return x.Procedure
+	}
+	return ""
+}
+
+func (x *MCPToolDescriptor) GetServiceFullName() string {
+	if x != nil {
+		return x.ServiceFullName
+	}
+	return ""
+}
+
+func (x *MCPToolDescriptor) GetMethodName() string {
+	if x != nil {
+		return x.MethodName
+	}
+	return ""
+}
+
+func (x *MCPToolDescriptor) GetDescription() string {
+	if x != nil {
+		return x.Description
+	}
+	return ""
+}
+
+func (x *MCPToolDescriptor) GetDocumentation() string {
+	if x != nil {
+		return x.Documentation
+	}
+	return ""
+}
+
+func (x *MCPToolDescriptor) GetInputSchemaJson() []byte {
+	if x != nil {
+		return x.InputSchemaJson
+	}
+	return nil
+}
+
 // PublicRoute is one site-root path claim (see PluginManifest.public_routes).
 type PublicRoute struct {
 	state protoimpl.MessageState `protogen:"open.v1"`
@@ -459,7 +560,7 @@ type PublicRoute struct {
 
 func (x *PublicRoute) Reset() {
 	*x = PublicRoute{}
-	mi := &file_v1_manifest_proto_msgTypes[1]
+	mi := &file_v1_manifest_proto_msgTypes[2]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -471,7 +572,7 @@ func (x *PublicRoute) String() string {
 func (*PublicRoute) ProtoMessage() {}
 
 func (x *PublicRoute) ProtoReflect() protoreflect.Message {
-	mi := &file_v1_manifest_proto_msgTypes[1]
+	mi := &file_v1_manifest_proto_msgTypes[2]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -484,7 +585,7 @@ func (x *PublicRoute) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use PublicRoute.ProtoReflect.Descriptor instead.
 func (*PublicRoute) Descriptor() ([]byte, []int) {
-	return file_v1_manifest_proto_rawDescGZIP(), []int{1}
+	return file_v1_manifest_proto_rawDescGZIP(), []int{2}
 }
 
 func (x *PublicRoute) GetPath() string {
@@ -513,7 +614,7 @@ type Dependency struct {
 
 func (x *Dependency) Reset() {
 	*x = Dependency{}
-	mi := &file_v1_manifest_proto_msgTypes[2]
+	mi := &file_v1_manifest_proto_msgTypes[3]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -525,7 +626,7 @@ func (x *Dependency) String() string {
 func (*Dependency) ProtoMessage() {}
 
 func (x *Dependency) ProtoReflect() protoreflect.Message {
-	mi := &file_v1_manifest_proto_msgTypes[2]
+	mi := &file_v1_manifest_proto_msgTypes[3]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -538,7 +639,7 @@ func (x *Dependency) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use Dependency.ProtoReflect.Descriptor instead.
 func (*Dependency) Descriptor() ([]byte, []int) {
-	return file_v1_manifest_proto_rawDescGZIP(), []int{2}
+	return file_v1_manifest_proto_rawDescGZIP(), []int{3}
 }
 
 func (x *Dependency) GetPlugin() string {
@@ -581,7 +682,7 @@ type BlockMeta struct {
 
 func (x *BlockMeta) Reset() {
 	*x = BlockMeta{}
-	mi := &file_v1_manifest_proto_msgTypes[3]
+	mi := &file_v1_manifest_proto_msgTypes[4]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -593,7 +694,7 @@ func (x *BlockMeta) String() string {
 func (*BlockMeta) ProtoMessage() {}
 
 func (x *BlockMeta) ProtoReflect() protoreflect.Message {
-	mi := &file_v1_manifest_proto_msgTypes[3]
+	mi := &file_v1_manifest_proto_msgTypes[4]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -606,7 +707,7 @@ func (x *BlockMeta) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use BlockMeta.ProtoReflect.Descriptor instead.
 func (*BlockMeta) Descriptor() ([]byte, []int) {
-	return file_v1_manifest_proto_rawDescGZIP(), []int{3}
+	return file_v1_manifest_proto_rawDescGZIP(), []int{4}
 }
 
 func (x *BlockMeta) GetKey() string {
@@ -672,7 +773,7 @@ type BlockTemplateOverride struct {
 
 func (x *BlockTemplateOverride) Reset() {
 	*x = BlockTemplateOverride{}
-	mi := &file_v1_manifest_proto_msgTypes[4]
+	mi := &file_v1_manifest_proto_msgTypes[5]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -684,7 +785,7 @@ func (x *BlockTemplateOverride) String() string {
 func (*BlockTemplateOverride) ProtoMessage() {}
 
 func (x *BlockTemplateOverride) ProtoReflect() protoreflect.Message {
-	mi := &file_v1_manifest_proto_msgTypes[4]
+	mi := &file_v1_manifest_proto_msgTypes[5]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -697,7 +798,7 @@ func (x *BlockTemplateOverride) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use BlockTemplateOverride.ProtoReflect.Descriptor instead.
 func (*BlockTemplateOverride) Descriptor() ([]byte, []int) {
-	return file_v1_manifest_proto_rawDescGZIP(), []int{4}
+	return file_v1_manifest_proto_rawDescGZIP(), []int{5}
 }
 
 func (x *BlockTemplateOverride) GetTemplateKey() string {
@@ -733,7 +834,7 @@ type SystemTemplateMeta struct {
 
 func (x *SystemTemplateMeta) Reset() {
 	*x = SystemTemplateMeta{}
-	mi := &file_v1_manifest_proto_msgTypes[5]
+	mi := &file_v1_manifest_proto_msgTypes[6]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -745,7 +846,7 @@ func (x *SystemTemplateMeta) String() string {
 func (*SystemTemplateMeta) ProtoMessage() {}
 
 func (x *SystemTemplateMeta) ProtoReflect() protoreflect.Message {
-	mi := &file_v1_manifest_proto_msgTypes[5]
+	mi := &file_v1_manifest_proto_msgTypes[6]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -758,7 +859,7 @@ func (x *SystemTemplateMeta) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use SystemTemplateMeta.ProtoReflect.Descriptor instead.
 func (*SystemTemplateMeta) Descriptor() ([]byte, []int) {
-	return file_v1_manifest_proto_rawDescGZIP(), []int{5}
+	return file_v1_manifest_proto_rawDescGZIP(), []int{6}
 }
 
 func (x *SystemTemplateMeta) GetKey() string {
@@ -797,7 +898,7 @@ type PageTemplateMeta struct {
 
 func (x *PageTemplateMeta) Reset() {
 	*x = PageTemplateMeta{}
-	mi := &file_v1_manifest_proto_msgTypes[6]
+	mi := &file_v1_manifest_proto_msgTypes[7]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -809,7 +910,7 @@ func (x *PageTemplateMeta) String() string {
 func (*PageTemplateMeta) ProtoMessage() {}
 
 func (x *PageTemplateMeta) ProtoReflect() protoreflect.Message {
-	mi := &file_v1_manifest_proto_msgTypes[6]
+	mi := &file_v1_manifest_proto_msgTypes[7]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -822,7 +923,7 @@ func (x *PageTemplateMeta) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use PageTemplateMeta.ProtoReflect.Descriptor instead.
 func (*PageTemplateMeta) Descriptor() ([]byte, []int) {
-	return file_v1_manifest_proto_rawDescGZIP(), []int{6}
+	return file_v1_manifest_proto_rawDescGZIP(), []int{7}
 }
 
 func (x *PageTemplateMeta) GetSystemKey() string {
@@ -876,7 +977,7 @@ type AdminPage struct {
 
 func (x *AdminPage) Reset() {
 	*x = AdminPage{}
-	mi := &file_v1_manifest_proto_msgTypes[7]
+	mi := &file_v1_manifest_proto_msgTypes[8]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -888,7 +989,7 @@ func (x *AdminPage) String() string {
 func (*AdminPage) ProtoMessage() {}
 
 func (x *AdminPage) ProtoReflect() protoreflect.Message {
-	mi := &file_v1_manifest_proto_msgTypes[7]
+	mi := &file_v1_manifest_proto_msgTypes[8]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -901,7 +1002,7 @@ func (x *AdminPage) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use AdminPage.ProtoReflect.Descriptor instead.
 func (*AdminPage) Descriptor() ([]byte, []int) {
-	return file_v1_manifest_proto_rawDescGZIP(), []int{7}
+	return file_v1_manifest_proto_rawDescGZIP(), []int{8}
 }
 
 func (x *AdminPage) GetKey() string {
@@ -953,7 +1054,7 @@ type AiAction struct {
 
 func (x *AiAction) Reset() {
 	*x = AiAction{}
-	mi := &file_v1_manifest_proto_msgTypes[8]
+	mi := &file_v1_manifest_proto_msgTypes[9]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -965,7 +1066,7 @@ func (x *AiAction) String() string {
 func (*AiAction) ProtoMessage() {}
 
 func (x *AiAction) ProtoReflect() protoreflect.Message {
-	mi := &file_v1_manifest_proto_msgTypes[8]
+	mi := &file_v1_manifest_proto_msgTypes[9]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -978,7 +1079,7 @@ func (x *AiAction) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use AiAction.ProtoReflect.Descriptor instead.
 func (*AiAction) Descriptor() ([]byte, []int) {
-	return file_v1_manifest_proto_rawDescGZIP(), []int{8}
+	return file_v1_manifest_proto_rawDescGZIP(), []int{9}
 }
 
 func (x *AiAction) GetKey() string {
@@ -1028,7 +1129,7 @@ type CssManifest struct {
 
 func (x *CssManifest) Reset() {
 	*x = CssManifest{}
-	mi := &file_v1_manifest_proto_msgTypes[9]
+	mi := &file_v1_manifest_proto_msgTypes[10]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -1040,7 +1141,7 @@ func (x *CssManifest) String() string {
 func (*CssManifest) ProtoMessage() {}
 
 func (x *CssManifest) ProtoReflect() protoreflect.Message {
-	mi := &file_v1_manifest_proto_msgTypes[9]
+	mi := &file_v1_manifest_proto_msgTypes[10]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -1053,7 +1154,7 @@ func (x *CssManifest) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use CssManifest.ProtoReflect.Descriptor instead.
 func (*CssManifest) Descriptor() ([]byte, []int) {
-	return file_v1_manifest_proto_rawDescGZIP(), []int{9}
+	return file_v1_manifest_proto_rawDescGZIP(), []int{10}
 }
 
 func (x *CssManifest) GetNpmPackages() map[string]string {
@@ -1094,7 +1195,7 @@ type DirectoryExtensions struct {
 
 func (x *DirectoryExtensions) Reset() {
 	*x = DirectoryExtensions{}
-	mi := &file_v1_manifest_proto_msgTypes[10]
+	mi := &file_v1_manifest_proto_msgTypes[11]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -1106,7 +1207,7 @@ func (x *DirectoryExtensions) String() string {
 func (*DirectoryExtensions) ProtoMessage() {}
 
 func (x *DirectoryExtensions) ProtoReflect() protoreflect.Message {
-	mi := &file_v1_manifest_proto_msgTypes[10]
+	mi := &file_v1_manifest_proto_msgTypes[11]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -1119,7 +1220,7 @@ func (x *DirectoryExtensions) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use DirectoryExtensions.ProtoReflect.Descriptor instead.
 func (*DirectoryExtensions) Descriptor() ([]byte, []int) {
-	return file_v1_manifest_proto_rawDescGZIP(), []int{10}
+	return file_v1_manifest_proto_rawDescGZIP(), []int{11}
 }
 
 func (x *DirectoryExtensions) GetBooleanFilterFields() []string {
@@ -1168,7 +1269,7 @@ type BadgeLabel struct {
 
 func (x *BadgeLabel) Reset() {
 	*x = BadgeLabel{}
-	mi := &file_v1_manifest_proto_msgTypes[11]
+	mi := &file_v1_manifest_proto_msgTypes[12]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -1180,7 +1281,7 @@ func (x *BadgeLabel) String() string {
 func (*BadgeLabel) ProtoMessage() {}
 
 func (x *BadgeLabel) ProtoReflect() protoreflect.Message {
-	mi := &file_v1_manifest_proto_msgTypes[11]
+	mi := &file_v1_manifest_proto_msgTypes[12]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -1193,7 +1294,7 @@ func (x *BadgeLabel) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use BadgeLabel.ProtoReflect.Descriptor instead.
 func (*BadgeLabel) Descriptor() ([]byte, []int) {
-	return file_v1_manifest_proto_rawDescGZIP(), []int{11}
+	return file_v1_manifest_proto_rawDescGZIP(), []int{12}
 }
 
 func (x *BadgeLabel) GetPositive() string {
@@ -1223,7 +1324,7 @@ type MasterPageDefinition struct {
 
 func (x *MasterPageDefinition) Reset() {
 	*x = MasterPageDefinition{}
-	mi := &file_v1_manifest_proto_msgTypes[12]
+	mi := &file_v1_manifest_proto_msgTypes[13]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -1235,7 +1336,7 @@ func (x *MasterPageDefinition) String() string {
 func (*MasterPageDefinition) ProtoMessage() {}
 
 func (x *MasterPageDefinition) ProtoReflect() protoreflect.Message {
-	mi := &file_v1_manifest_proto_msgTypes[12]
+	mi := &file_v1_manifest_proto_msgTypes[13]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -1248,7 +1349,7 @@ func (x *MasterPageDefinition) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use MasterPageDefinition.ProtoReflect.Descriptor instead.
 func (*MasterPageDefinition) Descriptor() ([]byte, []int) {
-	return file_v1_manifest_proto_rawDescGZIP(), []int{12}
+	return file_v1_manifest_proto_rawDescGZIP(), []int{13}
 }
 
 func (x *MasterPageDefinition) GetKey() string {
@@ -1295,7 +1396,7 @@ type MasterPageBlock struct {
 
 func (x *MasterPageBlock) Reset() {
 	*x = MasterPageBlock{}
-	mi := &file_v1_manifest_proto_msgTypes[13]
+	mi := &file_v1_manifest_proto_msgTypes[14]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -1307,7 +1408,7 @@ func (x *MasterPageBlock) String() string {
 func (*MasterPageBlock) ProtoMessage() {}
 
 func (x *MasterPageBlock) ProtoReflect() protoreflect.Message {
-	mi := &file_v1_manifest_proto_msgTypes[13]
+	mi := &file_v1_manifest_proto_msgTypes[14]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -1320,7 +1421,7 @@ func (x *MasterPageBlock) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use MasterPageBlock.ProtoReflect.Descriptor instead.
 func (*MasterPageBlock) Descriptor() ([]byte, []int) {
-	return file_v1_manifest_proto_rawDescGZIP(), []int{13}
+	return file_v1_manifest_proto_rawDescGZIP(), []int{14}
 }
 
 func (x *MasterPageBlock) GetBlockKey() string {
@@ -1377,7 +1478,7 @@ type CoreServiceBinding struct {
 
 func (x *CoreServiceBinding) Reset() {
 	*x = CoreServiceBinding{}
-	mi := &file_v1_manifest_proto_msgTypes[14]
+	mi := &file_v1_manifest_proto_msgTypes[15]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -1389,7 +1490,7 @@ func (x *CoreServiceBinding) String() string {
 func (*CoreServiceBinding) ProtoMessage() {}
 
 func (x *CoreServiceBinding) ProtoReflect() protoreflect.Message {
-	mi := &file_v1_manifest_proto_msgTypes[14]
+	mi := &file_v1_manifest_proto_msgTypes[15]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -1402,7 +1503,7 @@ func (x *CoreServiceBinding) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use CoreServiceBinding.ProtoReflect.Descriptor instead.
 func (*CoreServiceBinding) Descriptor() ([]byte, []int) {
-	return file_v1_manifest_proto_rawDescGZIP(), []int{14}
+	return file_v1_manifest_proto_rawDescGZIP(), []int{15}
 }
 
 func (x *CoreServiceBinding) GetServiceName() string {
@@ -1423,7 +1524,7 @@ var File_v1_manifest_proto protoreflect.FileDescriptor
 
 const file_v1_manifest_proto_rawDesc = "" +
 	"\n" +
-	"\x11v1/manifest.proto\x12\x06abi.v1\"\xaf\x0e\n" +
+	"\x11v1/manifest.proto\x12\x06abi.v1\"\xe7\x0e\n" +
 	"\x0ePluginManifest\x12\x1f\n" +
 	"\vabi_version\x18\x01 \x01(\rR\n" +
 	"abiVersion\x12\x12\n" +
@@ -1465,10 +1566,19 @@ const file_v1_manifest_proto_rawDesc = "" +
 	"\rallowed_hosts\x18\" \x03(\tR\fallowedHosts\x12&\n" +
 	"\x0fmax_response_mb\x18# \x01(\rR\rmaxResponseMb\x128\n" +
 	"\rpublic_routes\x18$ \x03(\v2\x13.abi.v1.PublicRouteR\fpublicRoutes\x12\x18\n" +
-	"\asitemap\x18% \x01(\bR\asitemap\x1aB\n" +
+	"\asitemap\x18% \x01(\bR\asitemap\x126\n" +
+	"\tmcp_tools\x18& \x03(\v2\x19.abi.v1.MCPToolDescriptorR\bmcpTools\x1aB\n" +
 	"\x14RbacMethodRolesEntry\x12\x10\n" +
 	"\x03key\x18\x01 \x01(\tR\x03key\x12\x14\n" +
-	"\x05value\x18\x02 \x01(\tR\x05value:\x028\x01\"9\n" +
+	"\x05value\x18\x02 \x01(\tR\x05value:\x028\x01\"\xf2\x01\n" +
+	"\x11MCPToolDescriptor\x12\x1c\n" +
+	"\tprocedure\x18\x01 \x01(\tR\tprocedure\x12*\n" +
+	"\x11service_full_name\x18\x02 \x01(\tR\x0fserviceFullName\x12\x1f\n" +
+	"\vmethod_name\x18\x03 \x01(\tR\n" +
+	"methodName\x12 \n" +
+	"\vdescription\x18\x04 \x01(\tR\vdescription\x12$\n" +
+	"\rdocumentation\x18\x05 \x01(\tR\rdocumentation\x12*\n" +
+	"\x11input_schema_json\x18\x06 \x01(\fR\x0finputSchemaJson\"9\n" +
 	"\vPublicRoute\x12\x12\n" +
 	"\x04path\x18\x01 \x01(\tR\x04path\x12\x16\n" +
 	"\x06prefix\x18\x02 \x01(\bR\x06prefix\"a\n" +
@@ -1566,52 +1676,54 @@ func file_v1_manifest_proto_rawDescGZIP() []byte {
 	return file_v1_manifest_proto_rawDescData
 }
 
-var file_v1_manifest_proto_msgTypes = make([]protoimpl.MessageInfo, 19)
+var file_v1_manifest_proto_msgTypes = make([]protoimpl.MessageInfo, 20)
 var file_v1_manifest_proto_goTypes = []any{
 	(*PluginManifest)(nil),        // 0: abi.v1.PluginManifest
-	(*PublicRoute)(nil),           // 1: abi.v1.PublicRoute
-	(*Dependency)(nil),            // 2: abi.v1.Dependency
-	(*BlockMeta)(nil),             // 3: abi.v1.BlockMeta
-	(*BlockTemplateOverride)(nil), // 4: abi.v1.BlockTemplateOverride
-	(*SystemTemplateMeta)(nil),    // 5: abi.v1.SystemTemplateMeta
-	(*PageTemplateMeta)(nil),      // 6: abi.v1.PageTemplateMeta
-	(*AdminPage)(nil),             // 7: abi.v1.AdminPage
-	(*AiAction)(nil),              // 8: abi.v1.AiAction
-	(*CssManifest)(nil),           // 9: abi.v1.CssManifest
-	(*DirectoryExtensions)(nil),   // 10: abi.v1.DirectoryExtensions
-	(*BadgeLabel)(nil),            // 11: abi.v1.BadgeLabel
-	(*MasterPageDefinition)(nil),  // 12: abi.v1.MasterPageDefinition
-	(*MasterPageBlock)(nil),       // 13: abi.v1.MasterPageBlock
-	(*CoreServiceBinding)(nil),    // 14: abi.v1.CoreServiceBinding
-	nil,                           // 15: abi.v1.PluginManifest.RbacMethodRolesEntry
-	nil,                           // 16: abi.v1.CssManifest.NpmPackagesEntry
-	nil,                           // 17: abi.v1.DirectoryExtensions.BadgeLabelsEntry
-	nil,                           // 18: abi.v1.CoreServiceBinding.MethodRolesEntry
+	(*MCPToolDescriptor)(nil),     // 1: abi.v1.MCPToolDescriptor
+	(*PublicRoute)(nil),           // 2: abi.v1.PublicRoute
+	(*Dependency)(nil),            // 3: abi.v1.Dependency
+	(*BlockMeta)(nil),             // 4: abi.v1.BlockMeta
+	(*BlockTemplateOverride)(nil), // 5: abi.v1.BlockTemplateOverride
+	(*SystemTemplateMeta)(nil),    // 6: abi.v1.SystemTemplateMeta
+	(*PageTemplateMeta)(nil),      // 7: abi.v1.PageTemplateMeta
+	(*AdminPage)(nil),             // 8: abi.v1.AdminPage
+	(*AiAction)(nil),              // 9: abi.v1.AiAction
+	(*CssManifest)(nil),           // 10: abi.v1.CssManifest
+	(*DirectoryExtensions)(nil),   // 11: abi.v1.DirectoryExtensions
+	(*BadgeLabel)(nil),            // 12: abi.v1.BadgeLabel
+	(*MasterPageDefinition)(nil),  // 13: abi.v1.MasterPageDefinition
+	(*MasterPageBlock)(nil),       // 14: abi.v1.MasterPageBlock
+	(*CoreServiceBinding)(nil),    // 15: abi.v1.CoreServiceBinding
+	nil,                           // 16: abi.v1.PluginManifest.RbacMethodRolesEntry
+	nil,                           // 17: abi.v1.CssManifest.NpmPackagesEntry
+	nil,                           // 18: abi.v1.DirectoryExtensions.BadgeLabelsEntry
+	nil,                           // 19: abi.v1.CoreServiceBinding.MethodRolesEntry
 }
 var file_v1_manifest_proto_depIdxs = []int32{
-	2,  // 0: abi.v1.PluginManifest.dependencies:type_name -> abi.v1.Dependency
-	3,  // 1: abi.v1.PluginManifest.blocks:type_name -> abi.v1.BlockMeta
-	4,  // 2: abi.v1.PluginManifest.block_template_overrides:type_name -> abi.v1.BlockTemplateOverride
-	5,  // 3: abi.v1.PluginManifest.system_templates:type_name -> abi.v1.SystemTemplateMeta
-	6,  // 4: abi.v1.PluginManifest.page_templates:type_name -> abi.v1.PageTemplateMeta
-	7,  // 5: abi.v1.PluginManifest.admin_pages:type_name -> abi.v1.AdminPage
-	12, // 6: abi.v1.PluginManifest.master_pages:type_name -> abi.v1.MasterPageDefinition
-	8,  // 7: abi.v1.PluginManifest.ai_actions:type_name -> abi.v1.AiAction
-	15, // 8: abi.v1.PluginManifest.rbac_method_roles:type_name -> abi.v1.PluginManifest.RbacMethodRolesEntry
-	9,  // 9: abi.v1.PluginManifest.css_manifest:type_name -> abi.v1.CssManifest
-	10, // 10: abi.v1.PluginManifest.directory_extensions:type_name -> abi.v1.DirectoryExtensions
-	14, // 11: abi.v1.PluginManifest.core_service_bindings:type_name -> abi.v1.CoreServiceBinding
-	1,  // 12: abi.v1.PluginManifest.public_routes:type_name -> abi.v1.PublicRoute
-	16, // 13: abi.v1.CssManifest.npm_packages:type_name -> abi.v1.CssManifest.NpmPackagesEntry
-	17, // 14: abi.v1.DirectoryExtensions.badge_labels:type_name -> abi.v1.DirectoryExtensions.BadgeLabelsEntry
-	13, // 15: abi.v1.MasterPageDefinition.blocks:type_name -> abi.v1.MasterPageBlock
-	18, // 16: abi.v1.CoreServiceBinding.method_roles:type_name -> abi.v1.CoreServiceBinding.MethodRolesEntry
-	11, // 17: abi.v1.DirectoryExtensions.BadgeLabelsEntry.value:type_name -> abi.v1.BadgeLabel
-	18, // [18:18] is the sub-list for method output_type
-	18, // [18:18] is the sub-list for method input_type
-	18, // [18:18] is the sub-list for extension type_name
-	18, // [18:18] is the sub-list for extension extendee
-	0,  // [0:18] is the sub-list for field type_name
+	3,  // 0: abi.v1.PluginManifest.dependencies:type_name -> abi.v1.Dependency
+	4,  // 1: abi.v1.PluginManifest.blocks:type_name -> abi.v1.BlockMeta
+	5,  // 2: abi.v1.PluginManifest.block_template_overrides:type_name -> abi.v1.BlockTemplateOverride
+	6,  // 3: abi.v1.PluginManifest.system_templates:type_name -> abi.v1.SystemTemplateMeta
+	7,  // 4: abi.v1.PluginManifest.page_templates:type_name -> abi.v1.PageTemplateMeta
+	8,  // 5: abi.v1.PluginManifest.admin_pages:type_name -> abi.v1.AdminPage
+	13, // 6: abi.v1.PluginManifest.master_pages:type_name -> abi.v1.MasterPageDefinition
+	9,  // 7: abi.v1.PluginManifest.ai_actions:type_name -> abi.v1.AiAction
+	16, // 8: abi.v1.PluginManifest.rbac_method_roles:type_name -> abi.v1.PluginManifest.RbacMethodRolesEntry
+	10, // 9: abi.v1.PluginManifest.css_manifest:type_name -> abi.v1.CssManifest
+	11, // 10: abi.v1.PluginManifest.directory_extensions:type_name -> abi.v1.DirectoryExtensions
+	15, // 11: abi.v1.PluginManifest.core_service_bindings:type_name -> abi.v1.CoreServiceBinding
+	2,  // 12: abi.v1.PluginManifest.public_routes:type_name -> abi.v1.PublicRoute
+	1,  // 13: abi.v1.PluginManifest.mcp_tools:type_name -> abi.v1.MCPToolDescriptor
+	17, // 14: abi.v1.CssManifest.npm_packages:type_name -> abi.v1.CssManifest.NpmPackagesEntry
+	18, // 15: abi.v1.DirectoryExtensions.badge_labels:type_name -> abi.v1.DirectoryExtensions.BadgeLabelsEntry
+	14, // 16: abi.v1.MasterPageDefinition.blocks:type_name -> abi.v1.MasterPageBlock
+	19, // 17: abi.v1.CoreServiceBinding.method_roles:type_name -> abi.v1.CoreServiceBinding.MethodRolesEntry
+	12, // 18: abi.v1.DirectoryExtensions.BadgeLabelsEntry.value:type_name -> abi.v1.BadgeLabel
+	19, // [19:19] is the sub-list for method output_type
+	19, // [19:19] is the sub-list for method input_type
+	19, // [19:19] is the sub-list for extension type_name
+	19, // [19:19] is the sub-list for extension extendee
+	0,  // [0:19] is the sub-list for field type_name
 }
 
 func init() { file_v1_manifest_proto_init() }
@@ -1619,14 +1731,14 @@ func file_v1_manifest_proto_init() {
 	if File_v1_manifest_proto != nil {
 		return
 	}
-	file_v1_manifest_proto_msgTypes[13].OneofWrappers = []any{}
+	file_v1_manifest_proto_msgTypes[14].OneofWrappers = []any{}
 	type x struct{}
 	out := protoimpl.TypeBuilder{
 		File: protoimpl.DescBuilder{
 			GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
 			RawDescriptor: unsafe.Slice(unsafe.StringData(file_v1_manifest_proto_rawDesc), len(file_v1_manifest_proto_rawDesc)),
 			NumEnums:      0,
-			NumMessages:   19,
+			NumMessages:   20,
 			NumExtensions: 0,
 			NumServices:   0,
 		},

docs/adr/0001-plugin-manifests-publish-mcp-descriptors.md

@@ -0,0 +1,31 @@
+# Plugin manifests publish MCP descriptors
+
+CMS plugins expose ConnectRPC services with method-role mappings. The host can
+turn those unary methods into MCP tools, but a wasm plugin previously carried
+only its RBAC map; the host had no protobuf method descriptions or input
+schemas from which to build a safe MCP catalogue.
+
+Decision: `PluginManifest` carries repeated `MCPToolDescriptor` values at field
+38. The Go guest binding derives descriptors from linked protobuf reflection,
+includes only mapped unary methods, emits JSON object input schemas, and omits
+methods it cannot describe. The host remains responsible for validating every
+descriptor against the manifest RBAC map before registration.
+
+Generating descriptors from handwritten plugin metadata was rejected because
+it would duplicate protobuf definitions and drift from the actual service.
+Publishing every reflected method was rejected because tools without explicit
+RBAC mappings would widen the plugin's callable surface.
+
+Consequences:
+
+- Wasm plugin manifests can advertise their own ConnectRPC methods as MCP tools.
+- Descriptor capture fails closed for missing services, streaming methods, and
+  malformed or unsupported protobuf inputs.
+- Consumers must use pluginsdk v0.3.2 or newer before calling
+  `PluginManifest.GetMcpTools`.
+- `abi/proto/v1/manifest.proto` remains the language-neutral source of truth;
+  `abi/v1/manifest.pb.go` is generated output.
+
+Keywords: PluginManifest, MCPToolDescriptor, mcp_tools, GetMcpTools,
+captureMCPTools, plugin/wasmguest/mcp.go, abi/proto/v1/manifest.proto,
+abi/v1/manifest.pb.go, ConnectRPC, MCP, RBAC, pluginsdk v0.3.2

plugin/wasmguest/describe.go

@@ -247,12 +247,14 @@ func (g *guest) captureServiceRegistration(m *abiv1.PluginManifest) {
 		if coreBound[svc.Name()] {
 			continue // declared via core_service_bindings, host mounts it
 		}
-		for method, role := range svc.MethodRoles() {
+		methodRoles := svc.MethodRoles()
+		for method, role := range methodRoles {
 			if m.RbacMethodRoles == nil {
 				m.RbacMethodRoles = make(map[string]string)
 			}
 			m.RbacMethodRoles[method] = string(role)
 		}
+		m.McpTools = append(m.McpTools, captureMCPTools(methodRoles)...)
 	}
 }
 

plugin/wasmguest/mcp.go

@@ -0,0 +1,206 @@
+package wasmguest
+
+import (
+	"encoding/json"
+	"sort"
+	"strings"
+	"unicode"
+
+	abiv1 "git.dev.alexdunmow.com/block/pluginsdk/abi/v1"
+	"git.dev.alexdunmow.com/block/pluginsdk/rbac"
+	"google.golang.org/protobuf/reflect/protoreflect"
+	"google.golang.org/protobuf/reflect/protoregistry"
+)
+
+// captureMCPTools resolves the plugin's registered Connect procedures through
+// the protobuf registry compiled into the guest. It emits only unary methods
+// that have an explicit RBAC mapping; the host repeats that RBAC intersection
+// before adding the definitions to its live MCP catalogue.
+func captureMCPTools(methodRoles map[string]rbac.Role) []*abiv1.MCPToolDescriptor {
+	procedures := make([]string, 0, len(methodRoles))
+	for procedure := range methodRoles {
+		procedures = append(procedures, procedure)
+	}
+	sort.Strings(procedures)
+
+	tools := make([]*abiv1.MCPToolDescriptor, 0, len(procedures))
+	for _, procedure := range procedures {
+		serviceName, methodName, ok := splitConnectProcedure(procedure)
+		if !ok {
+			continue
+		}
+		desc, err := protoregistry.GlobalFiles.FindDescriptorByName(protoreflect.FullName(serviceName))
+		if err != nil {
+			continue
+		}
+		service, ok := desc.(protoreflect.ServiceDescriptor)
+		if !ok {
+			continue
+		}
+		method := service.Methods().ByName(protoreflect.Name(methodName))
+		if method == nil || method.IsStreamingClient() || method.IsStreamingServer() {
+			continue
+		}
+
+		schema, err := json.Marshal(schemaForMessage(method.Input(), map[protoreflect.FullName]bool{}))
+		if err != nil {
+			continue
+		}
+		description, documentation := methodDocumentation(method)
+		tools = append(tools, &abiv1.MCPToolDescriptor{
+			Procedure:       procedure,
+			ServiceFullName: serviceName,
+			MethodName:      methodName,
+			Description:     description,
+			Documentation:   documentation,
+			InputSchemaJson: schema,
+		})
+	}
+	return tools
+}
+
+func splitConnectProcedure(procedure string) (serviceName, methodName string, ok bool) {
+	trimmed := strings.TrimPrefix(strings.TrimSpace(procedure), "/")
+	serviceName, methodName, ok = strings.Cut(trimmed, "/")
+	return serviceName, methodName, ok && serviceName != "" && methodName != "" && !strings.Contains(methodName, "/")
+}
+
+func methodDocumentation(method protoreflect.MethodDescriptor) (description, documentation string) {
+	location := method.ParentFile().SourceLocations().ByDescriptor(method)
+	documentation = strings.TrimSpace(location.LeadingComments)
+	paragraph := documentation
+	if before, _, ok := strings.Cut(paragraph, "\n\n"); ok {
+		paragraph = before
+	}
+	paragraph = strings.TrimSpace(strings.ReplaceAll(paragraph, "\n", " "))
+	methodName := string(method.Name())
+	if strings.HasPrefix(paragraph, methodName+" ") {
+		paragraph = strings.TrimSpace(strings.TrimPrefix(paragraph, methodName+" "))
+		if paragraph != "" {
+			runes := []rune(paragraph)
+			runes[0] = unicode.ToUpper(runes[0])
+			paragraph = string(runes)
+		}
+	}
+	if paragraph == "" {
+		paragraph = "Calls " + string(method.FullName()) + "."
+	}
+	return paragraph, documentation
+}
+
+func schemaForMessage(message protoreflect.MessageDescriptor, visited map[protoreflect.FullName]bool) map[string]any {
+	object := map[string]any{"type": "object"}
+	if message == nil || visited[message.FullName()] {
+		return object
+	}
+	visited[message.FullName()] = true
+	defer delete(visited, message.FullName())
+
+	properties := make(map[string]any, message.Fields().Len())
+	for i := range message.Fields().Len() {
+		field := message.Fields().Get(i)
+		properties[string(field.Name())] = fieldSchema(field, visited)
+	}
+	if len(properties) > 0 {
+		object["properties"] = properties
+	}
+	return object
+}
+
+func fieldSchema(field protoreflect.FieldDescriptor, visited map[protoreflect.FullName]bool) map[string]any {
+	var schema map[string]any
+	switch {
+	case field.IsMap():
+		schema = map[string]any{
+			"type":                 "object",
+			"additionalProperties": singularFieldSchema(field.MapValue(), visited),
+		}
+	case field.IsList():
+		schema = map[string]any{"type": "array", "items": singularFieldSchema(field, visited)}
+	default:
+		schema = singularFieldSchema(field, visited)
+	}
+
+	location := field.ParentFile().SourceLocations().ByDescriptor(field)
+	if comment := strings.TrimSpace(strings.ReplaceAll(location.LeadingComments, "\n", " ")); comment != "" {
+		schema["description"] = comment
+	}
+	return schema
+}
+
+func singularFieldSchema(field protoreflect.FieldDescriptor, visited map[protoreflect.FullName]bool) map[string]any {
+	switch field.Kind() {
+	case protoreflect.MessageKind, protoreflect.GroupKind:
+		return wellKnownOrMessage(field.Message(), visited)
+	case protoreflect.EnumKind:
+		return enumSchema(field.Enum())
+	default:
+		return scalarSchema(field.Kind())
+	}
+}
+
+func scalarSchema(kind protoreflect.Kind) map[string]any {
+	switch kind {
+	case protoreflect.BoolKind:
+		return map[string]any{"type": "boolean"}
+	case protoreflect.Int32Kind, protoreflect.Sint32Kind, protoreflect.Sfixed32Kind,
+		protoreflect.Uint32Kind, protoreflect.Fixed32Kind,
+		protoreflect.Int64Kind, protoreflect.Sint64Kind, protoreflect.Sfixed64Kind,
+		protoreflect.Uint64Kind, protoreflect.Fixed64Kind:
+		return map[string]any{"type": "integer"}
+	case protoreflect.FloatKind, protoreflect.DoubleKind:
+		return map[string]any{"type": "number"}
+	case protoreflect.StringKind:
+		return map[string]any{"type": "string"}
+	case protoreflect.BytesKind:
+		return map[string]any{"type": "string", "contentEncoding": "base64"}
+	default:
+		return map[string]any{}
+	}
+}
+
+func enumSchema(enum protoreflect.EnumDescriptor) map[string]any {
+	schema := map[string]any{"type": "string"}
+	if enum == nil {
+		return schema
+	}
+	values := make([]any, 0, enum.Values().Len())
+	for i := range enum.Values().Len() {
+		values = append(values, string(enum.Values().Get(i).Name()))
+	}
+	if len(values) > 0 {
+		schema["enum"] = values
+	}
+	return schema
+}
+
+func wellKnownOrMessage(message protoreflect.MessageDescriptor, visited map[protoreflect.FullName]bool) map[string]any {
+	if message == nil {
+		return map[string]any{"type": "object"}
+	}
+	switch message.FullName() {
+	case "google.protobuf.Timestamp":
+		return map[string]any{"type": "string", "format": "date-time"}
+	case "google.protobuf.Duration", "google.protobuf.FieldMask":
+		return map[string]any{"type": "string"}
+	case "google.protobuf.Struct":
+		return map[string]any{"type": "object"}
+	case "google.protobuf.ListValue":
+		return map[string]any{"type": "array"}
+	case "google.protobuf.Value", "google.protobuf.Any":
+		return map[string]any{}
+	case "google.protobuf.Empty":
+		return map[string]any{"type": "object"}
+	case "google.protobuf.StringValue", "google.protobuf.BytesValue":
+		return map[string]any{"type": "string"}
+	case "google.protobuf.BoolValue":
+		return map[string]any{"type": "boolean"}
+	case "google.protobuf.Int32Value", "google.protobuf.UInt32Value",
+		"google.protobuf.Int64Value", "google.protobuf.UInt64Value":
+		return map[string]any{"type": "integer"}
+	case "google.protobuf.FloatValue", "google.protobuf.DoubleValue":
+		return map[string]any{"type": "number"}
+	default:
+		return schemaForMessage(message, visited)
+	}
+}

plugin/wasmguest/mcp_test.go

@@ -0,0 +1,100 @@
+package wasmguest
+
+import (
+	"encoding/json"
+	"testing"
+
+	"git.dev.alexdunmow.com/block/pluginsdk/rbac"
+	"google.golang.org/protobuf/proto"
+	"google.golang.org/protobuf/reflect/protodesc"
+	"google.golang.org/protobuf/reflect/protoregistry"
+	"google.golang.org/protobuf/types/descriptorpb"
+	_ "google.golang.org/protobuf/types/known/timestamppb"
+)
+
+func TestCaptureMCPToolsUsesCompiledProtobufDescriptor(t *testing.T) {
+	registerMCPFixture(t)
+	procedure := "/mcpfixture.v1.WikiService/ListArticles"
+	tools := captureMCPTools(map[string]rbac.Role{procedure: rbac.RoleAdmin})
+	if len(tools) != 1 {
+		t.Fatalf("captureMCPTools() returned %d tools, want 1", len(tools))
+	}
+	tool := tools[0]
+	if tool.GetProcedure() != procedure || tool.GetServiceFullName() != "mcpfixture.v1.WikiService" || tool.GetMethodName() != "ListArticles" {
+		t.Fatalf("unexpected procedure metadata: %#v", tool)
+	}
+	if tool.GetDescription() != "Lists Wiki articles." || tool.GetDocumentation() != "ListArticles lists Wiki articles.\n\nSupports pagination." {
+		t.Fatalf("unexpected descriptor documentation: description=%q doc=%q", tool.GetDescription(), tool.GetDocumentation())
+	}
+	var schema map[string]any
+	if err := json.Unmarshal(tool.GetInputSchemaJson(), &schema); err != nil {
+		t.Fatalf("schema is not JSON: %v", err)
+	}
+	properties, ok := schema["properties"].(map[string]any)
+	if !ok {
+		t.Fatalf("schema properties = %#v", schema["properties"])
+	}
+	assertSchemaType(t, properties, "search", "string")
+	assertSchemaType(t, properties, "page", "integer")
+	assertSchemaType(t, properties, "published_after", "string")
+}
+
+func TestCaptureMCPToolsSkipsUnresolvableAndStreamingProcedures(t *testing.T) {
+	registerMCPFixture(t)
+	tools := captureMCPTools(map[string]rbac.Role{
+		"/mcpfixture.v1.WikiService/StreamArticles": rbac.RoleAdmin,
+		"/missing.v1.WikiService/ListArticles":      rbac.RoleAdmin,
+		"not-a-procedure":                           rbac.RoleAdmin,
+	})
+	if len(tools) != 0 {
+		t.Fatalf("captureMCPTools() returned %d tools, want fail-closed omission", len(tools))
+	}
+}
+
+func assertSchemaType(t *testing.T, properties map[string]any, field, expected string) {
+	t.Helper()
+	property, ok := properties[field].(map[string]any)
+	if !ok || property["type"] != expected {
+		t.Fatalf("schema field %q = %#v, want type %q", field, properties[field], expected)
+	}
+}
+
+func registerMCPFixture(t *testing.T) {
+	t.Helper()
+	if _, err := protoregistry.GlobalFiles.FindFileByPath("test/mcpfixture.proto"); err == nil {
+		return
+	}
+	file, err := protodesc.NewFile(&descriptorpb.FileDescriptorProto{
+		Name:       proto.String("test/mcpfixture.proto"),
+		Package:    proto.String("mcpfixture.v1"),
+		Syntax:     proto.String("proto3"),
+		Dependency: []string{"google/protobuf/timestamp.proto"},
+		MessageType: []*descriptorpb.DescriptorProto{{
+			Name: proto.String("ListArticlesRequest"),
+			Field: []*descriptorpb.FieldDescriptorProto{
+				{Name: proto.String("search"), Number: proto.Int32(1), Label: descriptorpb.FieldDescriptorProto_LABEL_OPTIONAL.Enum(), Type: descriptorpb.FieldDescriptorProto_TYPE_STRING.Enum()},
+				{Name: proto.String("page"), Number: proto.Int32(2), Label: descriptorpb.FieldDescriptorProto_LABEL_OPTIONAL.Enum(), Type: descriptorpb.FieldDescriptorProto_TYPE_INT32.Enum()},
+				{Name: proto.String("published_after"), Number: proto.Int32(3), Label: descriptorpb.FieldDescriptorProto_LABEL_OPTIONAL.Enum(), Type: descriptorpb.FieldDescriptorProto_TYPE_MESSAGE.Enum(), TypeName: proto.String(".google.protobuf.Timestamp")},
+			},
+		}, {
+			Name: proto.String("ListArticlesResponse"),
+		}},
+		Service: []*descriptorpb.ServiceDescriptorProto{{
+			Name: proto.String("WikiService"),
+			Method: []*descriptorpb.MethodDescriptorProto{{
+				Name: proto.String("ListArticles"), InputType: proto.String(".mcpfixture.v1.ListArticlesRequest"), OutputType: proto.String(".mcpfixture.v1.ListArticlesResponse"),
+			}, {
+				Name: proto.String("StreamArticles"), InputType: proto.String(".mcpfixture.v1.ListArticlesRequest"), OutputType: proto.String(".mcpfixture.v1.ListArticlesResponse"), ServerStreaming: proto.Bool(true),
+			}},
+		}},
+		SourceCodeInfo: &descriptorpb.SourceCodeInfo{Location: []*descriptorpb.SourceCodeInfo_Location{{
+			Path: []int32{6, 0, 2, 0}, Span: []int32{1, 0, 1, 1}, LeadingComments: proto.String("ListArticles lists Wiki articles.\n\nSupports pagination."),
+		}}},
+	}, protoregistry.GlobalFiles)
+	if err != nil {
+		t.Fatalf("create fixture descriptor: %v", err)
+	}
+	if err := protoregistry.GlobalFiles.RegisterFile(file); err != nil {
+		t.Fatalf("register fixture descriptor: %v", err)
+	}
+}