Every MCP server I've read that wraps a third-party REST API has the same shape: someone picked fifteen or twenty endpoints that seemed useful, hand-wrote a Zod schema for each, and shipped it.
That works for about three months.
Then the API adds a field, deprecates an enum value, renames a query parameter. The wrapper doesn't notice, because nothing in it is connected to the API's own description of itself. The schemas drift. The model starts getting rejected by the upstream API for reasons it can't see, and you get to debug an LLM guessing at a shape that stopped being true in February.
The other failure is quieter. You need endpoint twenty-one — the one about persistent disks, or scaling, or environment groups — and the author skipped it. Now you're back to curl, except the agent is holding half the context and you're holding the other half.
I wanted neither, so I built render-useful-mcp: an MCP server for Render where every API tool is generated from Render's own OpenAPI document. All 207 endpoints, no curation.
