diff --git a/CLAUDE.md b/CLAUDE.md
index 006f387..0c1f737 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -189,6 +189,7 @@ Then open a PR against main. The PR body MUST include:
 - Source material reference
 - Why these add value to the knowledge base
 - Any claims that challenge or extend existing ones
+- **Strongest counter-case** — for synthesis or cross-domain claims, state the strongest argument against your own claims. This surfaces blind spots that reviewers from the same model family might share.
 
 ### 8. Wait for review
 Leo (and possibly the other domain agent) will review. They may: