Resource freshness versus reading relevance

These examples and illustrative results are independently authored teaching materials, not measured model results.

Use case

Documentation was first read for an API signature, but the new task concerns errors. A teaching cache stores the original question ‘extract getItem signature’ and getItem(id): Item. The source is unchanged; its raw error section says not found→404 and unauthorized→403. Fresh source content does not make the old summary complete.

Mechanism

Inspect both resource identity/validators and the original extraction question. A signature-only summary cannot establish error behavior through freshness. Re-extract the error section from available raw content, or retrieve missing material when only the summary is available. Identify the range used and remaining unknowns in the new answer.

Bad example

The source validator returns 304, so reuse the old getItem(id): Item signature summary to answer 404/403 behavior without reading the error section.

Good example

Before answering getItem error semantics, inspect the cached original question and coverage. It extracted signatures only. Re-extract errors from the supplied unchanged raw document: 404 means not found and 403 means unauthorized. If raw material is absent, read the missing section. A 304 supports unchanged source content, not complete relevance of the earlier reading.

Why the change matters

A cache may contain one question-conditioned reading rather than the full document. Freshness addresses source changes; relevance addresses whether the reading covers this task. Separating them permits resource reuse without reusing omissions.

Observable expectation

An illustrative answer includes 404/403 and the error-section reference, treating the old summary as signature evidence only. If the source omits another error, preserve that unknown instead of inferring it from freshness or type signatures.

Check that the original question was inspected and current coverage established. ‘304, therefore trustworthy’ alone fails.

Limits

The source hook uses URL-only keys and surfaces the original extraction prompt for agent judgment; it does not automatically enforce re-extraction. This is a usage rule under that limitation, not a claim that every cache provides raw content or manual refresh.