api-endpoint-scaffold.txt
Build one endpoint: <METHOD> <path>

It should: <what it does>
Input: <fields and types>
Output on success: <shape>

Include, explicitly:
- Validation of every input, with what it returns when validation fails.
- The status code for each outcome, including not-found and not-allowed.
- What happens when the database call fails.

Match the style of this existing endpoint: <paste one>

Pasting an existing endpoint is worth more than any amount of description. Models copy patterns far more reliably than they follow instructions.