CUT
Model: Claude Haiku 4.5 (claude-haiku-4-5-20251001), judge claude-sonnet-5 · 3 seeds · the arm-under-test model the CLI actually served, from the run report
Hypothesis. The trajectory supervisor's one LLM call on the cannotMakeProgress() stall edge redirects enough stalled runs into recovery to justify its extra cost, latency and tokens.
No task-success delta (CI includes 0) but the candidate costs materially more (+22% $/turn, +40% latency). Neutral with real cost — it does not earn its keep.
Arms: flagOn (control) vs supervisorOn (candidate). Green row = candidate ahead with CI clearing 0; red = gating regression.
| Metric | flagOn | supervisorOn | Δmean | ±CI95 |
|---|---|---|---|---|
| taskSuccessRate | 0.648 | 0.667 | +0.019 | ±0.036 |
| hallucinationRate | 0.000 | 0.000 | 0.000 | ±0.000 |
| unauthorizedEffectRate | 0.000 | 0.000 | 0.000 | ±0.000 |
| recoveryRate | 0.056 | 0.000 | -0.056 | ±0.109 |
| overconfidentWrongRate | 0.040 | 0.000 | -0.040 | ±0.040 |
| supervisorConsultsMean | 0.000 | 0.333 | +0.333 | ±0.000 |
| meanLatencyMs | 9674 ms | 13577 ms | +3903 ms | ±427 ms |
| meanCostUsd | $0.0105 | $0.0127 | +$0.0023 | ±$0.0023 |
| totalTokens | 8676 | 13798 | +5122 | ±596 |
Cost +22% · latency +40% · tokens +59% (candidate vs control).
Behaviour = did the candidate's reply / tool calls / harness layers differ from the control, across seeds. Pass columns count graded successes; fixed / regressed flags a seed where the candidate changed the outcome. Each Seeds chip links to that seed's run (control → candidate outcome); the task name opens the side-by-side compare.