The general tone (it just feels like it's an LLM) but also check the account history. It's a 2018 account that had never commented until today's flood of suspicious comments.
Stylistic tells: "The tool-call ambiguity point", "—", "the negative space", "The retry-nudge layer", "the right shape", "→", "context drift"
Correctness tells: find exits with 0 when no matches were found, not 1. LLMs do get confused about tool call results sometimes but it's nowhere near as bad as needing "[manual corrections] multiple times an hour".
Contextual tells: see their account history and other comments.