mcp-builder

Build MCP servers in Python or TypeScript with validated tools and structured outputs.

Updated Jan 26, 2023
One-click install
npx skills add https://github.com/yuyalun-allen/dotfiles --skill mcp-builder-yuyalun-allen
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: mcp-builder
Source: https://github.com/yuyalun-allen/dotfiles/tree/main/tools/pi/agent/skills/mcp-builder
Command: npx skills add https://github.com/yuyalun-allen/dotfiles --skill mcp-builder-yuyalun-allen

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill requires anthropic, mcp, and includes scripts (resource) components.

What problem does it solve?

This guide helps developers design and build Model Context Protocol (MCP) servers that let large language models reliably interact with external services by defining clear tools, transports, schemas, and evaluation workflows.

Core Features & Use Cases

  • Research & Planning: Guidance on API coverage vs workflow tools, tool naming, and context management.
  • Language Guides: Concrete implementation patterns for TypeScript (Zod + MCP SDK) and Python (FastMCP + Pydantic).
  • Infrastructure & Testing: Connection helpers, evaluation harness, and best practices for pagination, error handling, and security.
  • Use Case: Integrate third-party APIs (e.g., GitHub, Slack) into LLM-driven workflows with robust, testable tools.

Quick Start

Run the provided evaluation harness against your MCP server to verify tool schemas, pagination, and agent workflows.

Frequently Asked Questions about mcp-builder

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I build an MCP server to let LLMs interact with external APIs?

You build an MCP server by defining clear tools, transports, and schemas that let LLMs interact with external services. This guide provides implementation patterns for API integration, tool registration, and structured outputs for agent workflows.

What's the best way to validate inputs for a Model Context Protocol server in Python or TypeScript?

Input validation for a Model Context Protocol server is handled using Pydantic for Python FastMCP implementations and Zod for TypeScript MCP SDK implementations, ensuring robust structured data schemas for your tools.

Does FastMCP support stdio and streamable HTTP transports for MCP servers?

Yes, FastMCP supports both stdio and streamable HTTP transports for MCP servers. The guide covers transport support alongside pagination metadata and actionable error messages for reliable external service communication.

How do I test MCP server tool schemas and pagination automatically?

You test MCP server tool schemas and pagination using the provided evaluation harness. It runs automated read-only testing against your server to verify tool schemas, pagination behavior, and overall agent workflows.

Can I use the MCP SDK to integrate third-party APIs like GitHub and Slack into LLM workflows?

Yes, you can use the MCP SDK to integrate third-party APIs like GitHub and Slack into LLM-driven workflows. The guide provides concrete patterns for connecting external services with robust, testable tools.

Why do I need structuredContent returns and tool annotations in my MCP server?

structuredContent returns and clear tool annotations are needed in your MCP server to ensure reliable context management and well-designed tool discovery. They enable LLMs to correctly parse outputs and understand tool purposes.