Your MCP server is not an API adapter

A lot of MCP servers I see in the wild look like this: @mcp.tool() async def get_thing(id: str): resp = await httpx.get(f"https://api.example.com/things/{id}") return resp.json() Fetch, forward, done. A thin HTTP proxy with a JSON Schema wrapper. For some use cases, that's enough. The servers I keep coming back to do something different. They hold state and pre-compute answers. An agent hitting a thin wrapper might need three round trips and 30 seconds. The same agent hitting a server that does