+1 on merging this or at least getting feedback from the team. I ran into this problem myself just today. Some of the error conditions that the API I'm wrapping for LLM consumption are complex and the better I can hint the LLM in the response, the better we'll be able to properly recover.

guys, can we get this merged

It's disappointing that @ksinder went to the trouble of creating a PR for this and it's been ignored for many months.

Can I get help with this please? #1148

This change was released in @modelcontextprotocol/[email protected]
I am using @modelcontextprotocol/[email protected] but still doesn't work for me
zod is a direct dependency in my project [email protected]

const schema = z.strictObject({
  key1: z.literal('value1'),
  key2: z.literal('value2'),
});

const mcpTool: Tool = {
  name: 'Test tool',
  description: 'Test tool',
  title: 'Test tool',
  // just a dummy input and output schema
  inputSchema: schema,
  outputSchema: schema,
};

InputSchema and outputSchema have the following error. TLDR: 'type' is missing

Property 'type' is missing in type 'ZodObject<{ key1: ZodLiteral<"value1">; key2: ZodLiteral<"value2">; }, "strict", ZodTypeAny, { key1: "value1"; key2: "value2"; }, { key1: "value1"; key2: "value2"; }>' but required in type '{ [x: string]: unknown; type: "object"; properties?: { [x: string]: object; } | undefined; required?: string[] | undefined; }'.

I think this pr is supposed to support the schema mentioned above directly. Please correct me if I am wrong
The code below works fine, without any errors. But i doubt if it is the correct version

const mcpTool: Tool = {
  name: 'Test tool',
  description: 'Test tool',
  title: 'Test tool',
  // just a dummy input and output schema
  inputSchema: { ...schema, type: 'object' },
  outputSchema: { ...schema, type: 'object' },
};

This change was released in @modelcontextprotocol/[email protected] I am using @modelcontextprotocol/[email protected] but still doesn't work for me zod is a direct dependency in my project [email protected]

const schema = z.strictObject({
  key1: z.literal('value1'),
  key2: z.literal('value2'),
});

const mcpTool: Tool = {
  name: 'Test tool',
  description: 'Test tool',
  title: 'Test tool',
  // just a dummy input and output schema
  inputSchema: schema,
  outputSchema: schema,
};

InputSchema and outputSchema have the following error. TLDR: 'type' is missing

Property 'type' is missing in type 'ZodObject<{ key1: ZodLiteral<"value1">; key2: ZodLiteral<"value2">; }, "strict", ZodTypeAny, { key1: "value1"; key2: "value2"; }, { key1: "value1"; key2: "value2"; }>' but required in type '{ [x: string]: unknown; type: "object"; properties?: { [x: string]: object; } | undefined; required?: string[] | undefined; }'.

I think this pr is supposed to support the schema mentioned above directly. Please correct me if I am wrong The code below works fine, without any errors. But i doubt if it is the correct version

const mcpTool: Tool = {
  name: 'Test tool',
  description: 'Test tool',
  title: 'Test tool',
  // just a dummy input and output schema
  inputSchema: { ...schema, type: 'object' },
  outputSchema: { ...schema, type: 'object' },
};

The issue was due to a difference in exported types from the sdk. I was using low-level server, and the type I used for creating the tool was Tool, where it should have been RegisteredTool don't know why there are two of them. Should be documented somewhere, or need to create a bug if these two are supposed to be used interchangeably

// GOOD 
import { RegisteredTool, RegisteredResource } from '@modelcontextprotocol/sdk/server/mcp';
// BAD
import {  Tool, Resource } from '@modelcontextprotocol/sdk/types';