Pattern 4

Tier by mechanical impact, not by tone

Problem. A system that auto-applies its own findings needs a line between "apply automatically" and "ask a human first." Drawing that line from how confident a finding sounds is a trap.

Pattern. Classify each change by mechanical reversibility. A typo fix and a deleted file sit in different tiers regardless of how the finding is worded. Low-impact, trivially reversible changes auto-apply; anything that deletes, publishes, or spends money gets a human gate.

Why this beats the obvious. Tone-based heuristics ("the finding says critical") are gameable and drift over time. Mechanical impact is a property of the action itself, not the language describing it.

Cost. An explicit impact table, kept current as new action types appear.

Where it lives: samples/.claude/agents/audit.md (the tier-classification table).

Seen in 3 of 8 teardowns · Practise: learn/04