AGENTS.md is a living doc — update when patterns recur

rule Thu Jul 02 2026 00:00:00 GMT+0000 (Coordinated Universal Time) agentagents-mdhygieneliving-docworkflow

AGENTS.md is a living doc

The rule

AGENTS.md is not a one-time write. When a pattern recurs during development, UPDATE AGENTS.md before moving on to the next feature.

Solve once → document → forget. Never fight the same issue twice.

Trigger: what counts as "recurring"

Update AGENTS.md when:

• Same tool quirk hits 2+ times in one session (e.g. NativeWind + safe-area-view style prop drops)
• AI reaches for wrong library / pattern more than once (e.g. keeps proposing lodash when stdlib works)
• Banned pattern appears in generated code multiple times (e.g. any type in TS, console.log left in)
• Version-specific gotcha surfaces (e.g. Zustand DevTools uses import.meta which RN doesn't support)
• User rejects a suggestion class more than once (e.g. "no card-on-file" for the Nth time)

The update mechanic

1. Note the issue as it happens (in a scratch section or inline)
2. At the natural stopping point (end of feature, before next prompt), edit AGENTS.md
3. Add a one-liner under the relevant section (Style Rules / Stack Rules / Anti-Patterns)
4. Continue the next feature — the AI now reads the updated AGENTS.md and skips the issue

Example

Situation: NativeWind class-name prop doesn't work on <SafeAreaView>. AI keeps generating class-name-only styles that silently fail.

Update: Add to AGENTS.md under Style Rules:

### Style Rules
- Use NativeWind classes (className prop) for all styling
- EXCEPTION: SafeAreaView does not support className. Use StyleSheet for it.

Now: AI reads this every prompt. Issue never returns.

Anti-patterns

• ❌ Fight the same issue 5 times without updating AGENTS.md
• ❌ Wait until "the perfect AGENTS.md" before starting — ship, update as you learn
• ❌ Bulk-update AGENTS.md quarterly — update SAME SESSION the issue appeared
• ❌ Add every one-off preference — only add things that RECUR
• ❌ Long-form additions — one-liners preferred; detail lives elsewhere

When to also propagate to knowledge/

If the recurring pattern is:

• Family-wide (affects all repos, not just this one) → also add to knowledge/rules/agent/ per agents-md-three-place-update
• Repo-specific → AGENTS.md only

AGENTS.md size discipline

AGENTS.md should grow slowly. If it's ballooning past ~500 lines:

• Some rules are one-offs, not recurring → prune them
• Some rules belong in a linked concept file → link out instead of inlining

Target: AGENTS.md is skimmable in 60 seconds by a new agent.

Cross-refs

• agents-md-three-place-update — when the update ALSO needs a knowledge/rules/ entry
• self-update-rule — the broader same-turn write discipline
• practical-vibe-coding — the umbrella this fits under
• Source: JavaScript Mastery YouTube 2026-07 "practical vibe coding" — the NativeWind + safe-area-view example