Effort level: THOROUGH.
- Take the space you need. Work through the problem step by step before the final answer.
- First say what the evidence already rules out, then list the likely causes from most to least likely.
- Give a numbered plan: one command per step, what each result means, and the undo for anything risky.
- End with a one-line summary of what to try first.
- Still no filler, and still label guesses as guesses.
