feat(ai): add mcp-metadata (#13150)

Co-authored-by: Félix Malfait <felix@twenty.com>

packages/twenty-server/src/engine/core-modules/ai/constants/mcp.const.ts

@@ -1,4 +1,7 @@
 export const MCP_SERVER_METADATA = {
+  metadata: {
+    info: '📦 Objects structure your business entities in Twenty. **Standard Objects** (e.g. People, Companies, Opportunities) are built‑in, pre‑configured data models. **Custom Objects** let you define entities specific to your needs (like Rockets, Properties, etc.). **Fields** work like spreadsheet columns and can be standard or custom. Always use the `fields` and `objects` parameters to select only the data you need—this **strongly reduces response size and token usage**, improving performance.',
+  },
   protocolVersion: '2024-11-05',
   serverInfo: {
     name: 'Twenty MCP Server',

packages/twenty-server/src/engine/core-modules/ai/dtos/json-rpc.ts

@@ -20,7 +20,10 @@ export class JsonRpc {
 
   @IsOptional()
   @IsObject()
-  params?: Record<string, unknown>;
+  params?: {
+    name: string;
+    arguments: unknown;
+  };
 
   @IsOptional()
   @Validate(IsNumberOrString)

packages/twenty-server/src/engine/core-modules/ai/services/mcp.service.ts

@@ -110,6 +110,7 @@ export class McpService {
         userWorkspaceId,
         apiKey,
       );
+
       const toolSet = await this.toolService.listTools(roleId, workspace.id);
 
       if (method === 'tools/call' && params) {

packages/twenty-server/src/engine/core-modules/ai/utils/wrap-jsonrpc-response.util.ts

@@ -5,14 +5,19 @@ export const wrapJsonRpcResponse = (
   payload:
     | Record<'result', Record<string, unknown>>
     | Record<'error', Record<string, unknown>>,
+  omitMetadata = false,
 ) => {
   const body =
     'result' in payload
       ? {
-          result: { ...payload.result, ...MCP_SERVER_METADATA },
+          result: omitMetadata
+            ? payload.result
+            : { ...payload.result, ...MCP_SERVER_METADATA },
         }
       : {
-          error: { ...payload.error, ...MCP_SERVER_METADATA },
+          error: omitMetadata
+            ? payload.error
+            : { ...payload.error, ...MCP_SERVER_METADATA },
         };
 
   return {