MCP Builder

Build high-quality MCP (Model Context Protocol) servers enabling LLMs to interact with external services through well-designed tools.

Four-Phase Development Process

Phase 1: Deep Research and Planning

• API Design Balance — Choose between comprehensive endpoint coverage or specialized workflow tools based on client needs
• Tool Naming — Use consistent prefixes (e.g., github_create_issue, github_list_repos) and action-oriented names
• Framework Choice — TypeScript recommended for SDK quality and broad AI model support
• Documentation Review — Start with MCP protocol sitemap, then study language-specific SDKs

Phase 2: Implementation

Set up project structure following language-specific guidelines:

• Build shared utilities (API client, error handling, pagination)
• Implement tools with:
  • Input schemas using Zod (TypeScript) or Pydantic (Python)
  • Output schemas for structured data
  • Clear descriptions and error messages
  • Proper annotations (readOnlyHint, destructiveHint, etc.)

Phase 3: Review and Test

• Verify code quality (no duplication, consistent error handling, full types)
• Build and test using MCP Inspector
• Run language-specific validation

Phase 4: Create Evaluations

• Design 10 complex, realistic evaluation questions
• Ensure questions are independent, read-only, and verifiable
• Format results as XML with question-answer pairs

Tool Naming Conventions

# Good
github_create_issue
github_list_repos
stripe_charge_card

# Avoid
create_issue (no prefix — ambiguous)
issueCreate (wrong casing)

Key Resources

• MCP Best Practices — Universal guidelines for naming, responses, and security
• Language Guides — Python (FastMCP) and TypeScript implementations
• Evaluation Guide — Comprehensive testing methodology
• MCP Inspector — Browser-based tool for interactive testing

Installation

npx skills add https://github.com/anthropics/skills --skill mcp-builder

Mirrored from https://github.com/anthropics/skills — original author: anthropics, license: Apache-2.0. This is an unclaimed mirror. Content and ownership transfer to the author when they claim this account.