seo-analyzer.md:278 listed "VSI (Visual Stability Index) — new 2026 signal,
Google Core Web Vitals 2.0" as a threshold, stated as fact, no hedge, in
client-facing audits. It does not exist.
Verified against two primary sources:
- developer.chrome.com/docs/crux/api — complete metric list carries no
visual_stability_index. Blogs claimed "Google is actively collecting VSI
through CrUX": flatly false.
- web.dev/articles/vitals — three stable CWV (LCP, INP, CLS). No VSI, no
"Core Web Vitals 2.0". Thresholds change with prior notice on an annual
cadence.
Ten SEO blogs cross-cited each other into an apparent consensus. WebSearch
returns that consensus, which is why the resources README rule "agents MUST
cross-check via WebSearch on FULL" did not catch it — that mitigation
launders blog misinformation into apparent verification.
Fix removes the metric and states the sourcing rule where a future rumour
would land: primary sources only (web.dev / Chromium blog / CrUX API list,
the last being decisive — a metric CrUX cannot return is one we cannot
score). Incident documented inline so it is not re-added.
Verified: make test 35 GREEN / 0 RED.
Bastien Chanot
4ea2fb8c37