Claude Code's prompt got 80% shorter — why less is more for Fable 5
anthropic reduced claude code's system prompt by 80% after finding that fable 5 models prefer fewer instructions and examples. this shifts how developers optimize ai models for better performance.
anthropic has reduced claude code's system prompt by 80%, discovering that its fable 5 models perform better with less rigid instruction. engineer tariq shihipar notes that adding examples now tends to constrain the model's imagination rather than guide it, marking a reversal from previous engineering trends. the company now prioritizes context-based steering over explicit 'do not do this' constraints. this suggests that as models scale, their interaction patterns must fundamentally change to maximize utility.