Copilot-Skills: Instructions file for GitHub Copilot

FastMCP Instructions

Auto-loaded when: **/*.py, **/mcp_*.py, **/*_server.py, **/fastmcp_*.py

Default Behaviors

When working with FastMCP code:

1. Use Type Hints: Always include type hints for tool parameters and return values
2. Document Functions: Add docstrings to all tools, resources, and prompts
3. Async When Possible: Prefer async functions for I/O operations
4. Error Handling: Implement proper error handling in tools
5. Follow MCP Patterns: Use FastMCP decorators (@mcp.tool, @mcp.resource, @mcp.prompt)

Common Workflows

Creating a New MCP Server

from fastmcp import FastMCP

# 1. Initialize server
mcp = FastMCP("Server Name")

# 2. Add tools
@mcp.tool
def my_tool(param: str) -> str:
    """Tool description"""
    return f"Result: {param}"

# 3. Run server
if __name__ == "__main__":
    mcp.run()  # or mcp.run(transport="http", port=8000)

Adding Resources

@mcp.resource("data://config")
def get_config() -> str:
    """Return configuration data"""
    return "config_content"

Adding Prompts

@mcp.prompt
def analyze_code(language: str, code: str) -> str:
    """Generate code analysis prompt"""
    return f"Analyze this {language} code:\n\n{code}"

Creating MCP Clients

import asyncio
from fastmcp import Client

async def main():
    async with Client("http://localhost:8000/mcp") as client:
        result = await client.call_tool(
            name="my_tool",
            arguments={"param": "value"}
        )
        print(result)

asyncio.run(main())

Quality Guidelines

✅ Do

• Use type hints for all parameters and return values
• Add descriptive docstrings to tools/resources/prompts
• Handle errors gracefully in tool implementations
• Use async/await for I/O operations
• Test tools independently before integration
• Use FastMCP's built-in authentication for security
• Deploy with FastMCP CLI for production

❌ Don't

• Skip type hints (they generate JSON schemas automatically)
• Forget docstrings (LLMs read them to understand tools)
• Use blocking I/O in async functions
• Expose sensitive data without authentication
• Hardcode configuration values
• Run production servers without proper error handling