mcp-builder
Guide for creating high-quality MCP (Model Context Protocol) servers that enable LLMs to interact with external services through well-designed tools. Use when building MCP servers to integrate external APIs or services, whether in Python (FastMCP), Node/TypeScript (MCP SDK), or C#/.NET (Microsoft MCP SDK).
83
73%
Does it follow best practices?
Impact
100%
2.50xAverage score across 3 eval scenarios
Advisory
Suggest reviewing before use
Optimize this skill with Tessl
npx tessl skill review --optimize ./.github/skills/mcp-builder/SKILL.mdEvaluation results
100%
72%Build a TypeScript MCP Server for a Task Management API
TypeScript MCP server structure and modern SDK usage
Server naming format
0%
100%
registerTool API usage
0%
100%
Zod strict schemas
0%
100%
Tool annotations present
0%
100%
structuredContent in responses
0%
100%
CHARACTER_LIMIT constant
0%
100%
Truncation message
0%
100%
response_format parameter
50%
100%
Strict TypeScript config
100%
100%
No any type
100%
100%
Build succeeds
100%
100%
Project structure
50%
100%
100%
73%Build a Python MCP Server for a Product Catalog API
Python MCP server with FastMCP and Pydantic v2
FastMCP import and init
0%
100%
Python server naming
0%
100%
Tool naming with service prefix
0%
100%
Pydantic v2 model_config
0%
100%
Pydantic v2 field_validator
0%
100%
Pagination metadata
40%
100%
response_format parameter
100%
100%
Shared error handler
0%
100%
Actionable error messages
62%
100%
No stdout logging
100%
100%
Async httpx usage
33%
100%
extra=forbid in models
0%
100%
100%
33%Build a Bookstore MCP Server and Write Its Evaluations
Tool naming, annotations, and MCP evaluation creation
Tool names have service prefix
0%
100%
Tool names snake_case
100%
100%
All four annotations present
0%
100%
Tool descriptions include examples
75%
100%
Tool descriptions include return schema
100%
100%
Transport selection rationale
100%
100%
No SSE transport
100%
100%
Evaluation XML format
50%
100%
10 QA pairs
0%
100%
Questions are read-only
100%
100%
Answers are single verifiable values
100%
100%
Questions require multiple steps
100%
100%
- Repository
- microsoft/agent-skills
- Commit
265cb08
- Evaluated
- Agent
- Claude Code
- Model
- Claude Sonnet 4.6
Table of Contents
Is this your skill?
If you maintain this skill, you can claim it as your own. Once claimed, you can manage eval scenarios, bundle related skills, attach documentation or rules, and ensure cross-agent compatibility.