Use this when

A workflow answers from sources that can go stale, and using an out-of-date source would produce wrong answers that look fine.

The pattern

NEED an answer from a source
      ↓
IS THE SOURCE FRESH ENOUGH?
  ├── Yes → use it
  └── No  → do not use it silently; flag or escalate

Each source carries a last-reviewed date. Before relying on it, the workflow checks that date against a freshness limit, and refuses to answer confidently from a source that is too old.

Why it works

Stale knowledge is one of the most common causes of confident, wrong answers, precisely because nothing looks broken. A freshness gate turns the invisible problem, an old source still being used, into a visible one: the workflow declines or flags rather than answering from outdated material. It makes keeping knowledge current enforceable rather than merely hoped for.

How to apply it

  1. Give each source a last-reviewed date and a freshness limit matched to how fast it changes.
  2. Before using a source, check it is within its limit.
  3. If it is past the limit, do not answer silently. Flag the answer as possibly stale, escalate, or prompt a review.
  4. Combine with cite the source so the age of the source travels with the answer.

Good fit

  • Prices, policies, product details, anything time-sensitive.
  • Retrieval systems drawing on documents that may not be maintained evenly.

Poor fit

  • Genuinely durable knowledge that does not go stale, where a gate adds friction for no benefit.

What this does not solve

A freshness gate stops the workflow using clearly outdated sources; it does not make a fresh source correct, and a source can be recently reviewed yet still wrong. It guards against staleness specifically, one important failure mode among several.