# Review by Principal Systems Engineer (Google/Stripe caliber) (Round 5)

## Review Complete

Here's my assessment as Principal Systems Engineer:

VERDICT: **approve**

FINDINGS:
- [src/colonyos/orchestrator.py]: Phase.FIX reuse for verify-fix limits audit granularity in logs — acceptable for v1, phase ordering disambiguates
- [src/colonyos/orchestrator.py]: `_verify_detected_failures()` fail-open on ambiguous output is correct design — structured sentinel makes the ambiguous case narrow
- [src/colonyos/orchestrator.py]: Dual budget guards (before verify AND before fix) follow review-loop pattern exactly — no resource leak path
- [src/colonyos/orchestrator.py]: Verify agent `allowed_tools` correctly restricted to `["Read", "Bash", "Glob", "Grep"]` at runtime — defense-in-depth
- [src/colonyos/orchestrator.py]: Hard-block delivery via `_fail_run_log()` + `return log` enforces core invariant "never open a broken PR"
- [src/colonyos/config.py]: `_parse_verify_config()` validates `max_fix_attempts >= 1` preventing misconfiguration
- [src/colonyos/config.py]: No haiku default for Phase.VERIFY — users can override, non-blocking for v1
- [src/colonyos/instructions/verify_fix.md]: Raw `{test_failure_output}` interpolated without sanitization — accepted risk, consistent with existing threat model

SYNTHESIS:
This is a well-engineered implementation that follows existing patterns precisely. Every critical failure mode is handled: budget exhaustion, agent crashes, ambiguous output, resume after failure. The core invariant — never open a PR you know is broken — is enforced through multiple layers: runtime tool restriction, structured sentinel parsing with robust fallback, dual budget guards, and hard-block delivery. The two-agent separation (read-only verify, write-enabled fix) preserves clean audit boundaries. 55 tests cover the decision boundary, pipeline integration, config, and resume paths. All 9 PRD functional requirements are implemented. No regressions in the existing 3110 tests. Ship it.
