principle-encode-lessons-in-structure

# Encode Lessons in Structure Encode recurring fixes in mechanisms (tools, code, metadata, automation) instead of textual instructions. Every error, human correction, and unexpected outcome is a learning signal. Capture it, route it, and close the loop. Textual instructions are easy to miss. Structural mechanisms enforce the rule without cooperation. **Pattern:** When you catch yourself writing the same instruction a second time: 1. Ask: can this be a lint rule, a metadata flag, a runtime check, or a script? 2. If yes, encode it. Delete the instruction 3. If no (requires judgment), make the instruction more prominent and add an example of the failure mode **Pick the strongest mechanism.** When more than one mechanism would work, choose the strongest the situation allows (an unrepresentable state that cannot compile, then a lint or banned API that fails CI, then a canonical helper, then a runtime check), because agents copy whatever the surrounding code already does and a weaker guard becomes the next template. **Corollary:** If the fix is structural, only use the structural fix. The instruction is the symptom. When the human intervenes or tests fail, decide if it's a one-off or a pattern. Route it: one-off -> brain note, recurring fix -> skill or lint rule, systemic issue -> principle. Close the loop: don't just record; apply now or create a concrete todo. **Anti-patterns:** - Acknowledging without recording ("I'll keep that in mind" does not persist) - Recording without routing (a brain note about a lint rule that should exist is wasted unless the lint rule gets implemented) - Fixing without generalizing (fixing one instance while leaving the recurring pattern intact)