An MCP server of your own

Done when

• At least three tools that do something you actually want, not a wrapper around a public API you never use
• Schemas with enums and bounded parameters rather than free-form strings, and errors that say what to do differently
• Works in Claude and in Cursor, with the configuration for both in the README
• A written threat note: what the server can reach, what it refuses, and what you deliberately did not expose
• Installable by a stranger from the README alone, with no undocumented environment assumptions

Nobody marks this for you. It goes into your phase checkpoint, where a person does.