Trouble with defining schema

[rpurinton]

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Question Category

• Protocol Specification
• SDK Usage
• Server Implementation
• General Implementation
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Your Question

I'm trying to define a tool that accepts an array of objects example:

import { z } from 'zod';

const taskSchema = z.object({
  details: z.string().max(10000).optional(),
  parent_id: z.number().optional(),
  scheduled_time: z.string().optional(),
  sort_order: z.number().optional(),
  status: z.enum([
    'pending',
    'in progress',
    'on hold',
    'blocked',
    'review',
    'cancelled',
    'completed',
  ]).optional(),
  title: z.string(),
});

const schema = z.object({
  tasks: z.array(taskSchema).min(1).describe('Array of tasks to create.'),
});


export default async function (server, toolName = 'task-create') {
  server.tool(
    toolName,
    'Creates one or more tasks. Returns an array of the task IDs that were created.',
    schema,
    async (args, extra) => { 
    ......

and this is what the openai mcp client sees:

      "type": "mcp_list_tools",
     "server_label": "tasklist",
     "tools": [
       {
         "annotations": null,
         "description": "Creates one or more tasks. Returns an array of the task IDs that were created.",
         "input_schema": {
           "type": "object"
         },
         "name": "task-create"
       },

what am i missing?

checking the mcp list/tools response

{
    "result": {
        "tools": [
            {
                "name": "task-create",
                "description": "Creates one or more tasks. Returns an array of the task IDs that were created.",
                "inputSchema": {
                    "type": "object"
                },
                "annotations": {
                    "type": "object",
                    "properties": {
                        "tasks": {
                            "type": "array",
                            "items": {
                                "type": "object",
                                "properties": {
                                    "details": {
                                        "type": "string",
                                        "maxLength": 10000
                                    },
                                    "parent_id": {
                                        "type": "number"
                                    },
                                    "scheduled_time": {
                                        "type": "string"
                                    },
                                    "sort_order": {
                                        "type": "number"
                                    },
                                    "status": {
                                        "type": "string",
                                        "enum": [
                                            "pending",
                                            "in progress",
                                            "on hold",
                                            "blocked",
                                            "review",
                                            "cancelled",
                                            "completed"
                                        ]
                                    },
                                    "title": {
                                        "type": "string"
                                    }
                                },
                                "required": [
                                    "title"
                                ],
                                "additionalProperties": false
                            },
                            "minItems": 1
                        }
                    },
                    "required": [
                        "tasks"
                    ],
                    "additionalProperties": false,
                    "$schema": "http://json-schema.org/draft-07/schema#"
                }
            },
            ...
            ```
            
            
 
    

[rpurinton]

resolved.

the problem is here:

const schema = z.object({
  tasks: z.array(taskSchema).min(1).describe('Array of tasks to create.'),
});

change to

const schema = {
  tasks: z.array(taskSchema).min(1).describe('Array of tasks to create.'),
};

Ie: no outer z.object wrapper