Anthropic Cut Claude Fable 5's Biology Fallbacks By 85 Percent: What The Classifier Rewrite Actually Means For Clinicians, Payers, Pharma R&D, And Anyone Buying Health AI On A Platform Contract

Anthropic just reported an 85% drop in biology-related fallbacks for Claude Fable 5. Here is what that number actually tells you, and what it leaves out.

Fable 5 launched in June with a classifier so conservative it blocked nearly all biology queries by design. The fix was a full taxonomy rewrite, expert review, new training data, and a retrain. Routine …