# Review: Andrej Karpathy — Round 4

**Branch:** `colonyos/when_you_output_followups_in_the_thread_on_slack_a938599349`
**PRD:** `cOS_prds/20260331_190640_prd_you_are_a_code_assistant_working_on_behalf_of_the_engineering_team_the_following.md`
**Round:** 4
**Tests:** 137 pass (test_slack_formatting.py + test_sanitize.py)
**Commits:** 11 (+1,371 / -24 lines)

## Checklist

### Completeness
- [x] FR-1: Task completion messages include description (truncated to 72 chars via `_SLACK_TASK_DESC_MAX`)
- [x] FR-2: Task outline uses bullet formatting (`*header:*` + `• task` lines, `+N more` overflow)
- [x] FR-3: Task result summary includes descriptions with cost/duration
- [x] FR-4: Review round messages include finding summaries (3-tier fallback: FINDINGS → SYNTHESIS → first line)
- [x] FR-5: Sanitization of all user-derived content (`sanitize_untrusted_content` + `sanitize_for_slack`)
- [x] All tasks complete, no placeholder/TODO code

### Quality
- [x] 137 tests pass
- [x] Code follows existing project conventions
- [x] No unnecessary dependencies
- [x] No unrelated changes

### Safety
- [x] No secrets in committed code
- [x] Sanitization applied at all 7 content ingress points
- [x] Error handling present (ValueError/TypeError on cost/duration with debug logging)

## Assessment

Both non-blocking findings from round 3 have been addressed:

1. **Debug logging for malformed cost/duration** — `logger.debug("Skipping malformed cost/duration for task %s: cost=%r, dur=%r", ...)` now replaces the bare `pass`. Good. Test `test_malformed_cost_logs_debug` verifies it.

2. **Tighter blank-line handling in findings collection** — Blank lines are now only tolerated while `len(findings_lines) < max_findings`. Once enough findings are collected, a blank line stops the state machine. Test `test_blank_lines_stop_after_max_findings` verifies the boundary. This is the correct fix — it makes the parser fail-closed rather than fail-open.

## Findings (None blocking)

No new findings. The implementation is clean and complete.

VERDICT: approve

FINDINGS:
- (none)

SYNTHESIS:
This is a well-executed feature that follows the cardinal rule of LLM application engineering: apply deterministic post-processing to semi-structured model output, degrade gracefully when structure is absent. The three-tier fallback in `_extract_review_findings_summary()` handles real-world variance of stochastic outputs without overengineering. Zero new LLM calls — all signal extracted from existing artifacts via simple string operations. Sanitization is applied at the content boundary (where untrusted data enters) with correct ordering (XML strip first, then Slack-specific escaping). The 137-test suite provides comprehensive coverage including integration tests through the full formatting chain. All four rounds of review findings have been addressed. Ship it.
