one-sentence-test

Write one concrete sentence naming the API's objects, verbs, and scope, then check every command or endpoint against it. Surfaces that serve no verb in the sentence are orphaned; verbs with no surface are gaps.

Apply three reductions: describe what the code body does ignoring docs, specialize that under the defaults actually in use, then check whether the caller needs that behavior. Defaults like Infinity or null often disable the advertised feature entirely.

Use it when auditing coherence of a design or questioning an abstraction's value, not for plain code-comprehension questions. A direct 'what does this function do' question gets a direct answer, not the full reduction pass.

It is a coherence gate, not a complete spec, naming exercise, or marketing tagline. It detects opportunities like asymmetric wins but defers the actual decision and refusal process to other skills.

A drifting sentence means the design has not converged yet, and that instability is itself the finding. Name the ambiguity explicitly before continuing with implementation or further specification.