Source Health. The operational condition of an evidence source: whether it can be parsed, indexed, refreshed, cited, governed, and compared against its expected crawl or harvest state. A source may be relevant and still unhealthy; unhealthy sources should degrade confidence, route review, or stay out of model grounding until the defect is resolved.
Source health is what keeps governed evidence alive after the first successful fetch. Freshness, parser success, crawl drift, citation metadata, harvest manifests, and corpus approval are all health signals because they inform the admission decision and evidence eligibility for whether a source is still fit to ground a decision.
Approval changes are health changes. A source whose evidence approval state moves to pending, rejected, or revoked should stop grounding conclusions even if parsing still works.
Freshness is tracked as freshness state, not just a stored date, because the same source age can be acceptable for one use and disqualifying for another.
Source health is measured against a source snapshot: the system needs to know which version of the source it fetched before it can decide whether the source has drifted.
Unhealthy sources should feed a confidence gate so stale, broken, or unapproved evidence changes behavior instead of silently grounding a conclusion.