---
paths:
  - "**/*.{ts,tsx,js,jsx,mjs,cjs,py,rs,go,sol,sh,bash,zsh,c,h,cc,cpp,hpp,java,kt,rb,lua,zig,nix,swift,php,cs,ex}"
---

## Code comments

Budget: 1-3 lines. Write one only when an agent with the repo and thirty
seconds of grep would still get it wrong. That means one of:

- a landmine no test catches
- a fact not in the repo (deployed bytecode, chain quirk, library bug)
- a unit or epoch the type cannot carry (wei, ms, 18-dp)
- a MUST or MUST NOT a caller can break

Good:

> `// MUST read lastGoodPrice before fetchPrice — same eth_call state.`

Everything else: delete. Design rationale and rejected alternatives go in
`docs/`; leave a path. History is in git. No emphasis; ALL-CAPS only for
MUST / NEVER.

Deleting a comment is cheap and reversible. When unsure, delete.