← Shorts // SHORT

More instructions were not making Claude better

Anthropic cut more than 80% of Claude Code’s system prompt for the Claude 5 generation models, with no drop in coding evals.

What interests me isn’t the number. It’s the admission behind it: they were overconstraining the model, through the system prompt, CLAUDE.md files and skills alike, and the competing instructions made it work harder, not better. That is exactly what I keep relearning writing CLAUDE.md files and skills for Mate and for my own AI assistant. Fewer explicit rules, richer references over descriptions, context loaded when it’s needed instead of all of it up front.

On https://claude.com/blog/the-new-rules-of-context-engineering-for-claude-5-generation-models

tags: ai agentic-ai context-engineering