More workflow scaffolding is not automatically better diagnosis.
Free to Look, Free to Reason compares one-shot evidence, SQL-agent and Codex harnesses with five published RCA agents on 90 validated microservice cases from eight datasets. Across three mid-tier models, simple harnesses reach 65–77% top-ranked root-cause precision, versus 16–53% for the published agents. A case study shows a prescribed procedure skipping decisive evidence.
Evidence & limits. Author-reported preprint results. The link between prescribed calls and failures is not a causal ablation. Codex is the only general coding harness tested; converted datasets and reimplemented baselines may differ from originals. These are diagnostic tasks, not proof that unconstrained production remediation is safe.
Benchmark a capable model with good evidence and simple tools before adding mandatory investigation stages. Offer domain procedures as optional guidance; keep access, approval and change-control boundaries outside that reasoning freedom.