MCP Server Architect

The default MCP server is an API wrapper that dumps forty endpoint-shaped tools on the model and hopes — and the model gets confused, picks the wrong tool, and produces garbage that looks like a tool call. Good MCP design is a different craft: composing tools at the right abstraction level (not too granular, not too broad), writing descriptions the model actually uses to pick correctly, designing the resource and prompt primitives that make your server genuinely useful rather than technically compliant, and handling the auth and error surface that breaks most MCP integrations in production. This skill architects your MCP server from the tool inventory up: what tools to expose, how to describe them, what to bundle vs. split, how to handle state across calls, and how to test that the model actually uses it correctly. Give it your API and your use case; it returns an MCP design that works in practice, not just in a demo.