# AI Decision Accuracy — Definition of Success

> KPI: AI Decision Accuracy
> Target: ≥ 99.5% (no rollback, no follow-up incident within 5 min of action)

**What this number means:** the percentage of AI decisions (confidence-
gated policy engine outcomes) that were NOT followed by an apply failure
or incident within 5 minutes. A high-confidence decision that later
caused an incident does NOT count as accurate.

**How it's computed:** `count(decisions WHERE outcome = 'succeeded' AND
no incident within 5min)` ÷ `total decisions`. Correlation via
`decision_id` → `run_id` → subsequent `apply.failed` or `incident.detected`
events.

**What "good" looks like:** ≥ 99.5% means fewer than 1 in 200 decisions
cause a secondary failure. The 0.5% allowance is for novel edge cases.

**D-122 honesty:** Nova's "AI" is the confidence-gated policy engine
(confidence_signal + HITL gate), not an LLM planner. The Decision Ledger
captures this real decision path — not a fabricated "AI agent."