Yanli Liu's " The 4 Lines Every CLAUDE.md Needs " makes a real point. The 4 lines, derived from Andrej Karpathy's January 2026 thread on agent failure modes, all express the same insight: behavioral rules outperform feature rules. Don't assume. Surface tradeoffs. Minimum code that solves the problem. Touch only what you must. Define success criteria. Loop until verified. Each one is portable across stacks and tasks, where prescriptive rules go stale the moment your codebase shifts. The 4 lines are the floor of a working CLAUDE.md. They are not the ceiling. Most of the CLAUDE.md files I see in the wild — including the ones the article holds up as cautionary tales of "47 rules about code style" — fail because they treat a file as the unit of organization. A production CLAUDE.md is an architecture, not a file.…