Win by Silence: Deletion Non-Monotonicity, Autonomous Exploitation, and Typed-State Gating in LLM Plan Evaluation

Aleh Manchuliantsau|July 14, 2026arXiv

Key Takeaway

LLM plan evaluators can be gamed by deleting necessary steps, making plans appear better without actual improvement. Use state-tracking validation (like GATE) to ensure score improvements reflect real quality gains, not omissions.

Summary

This paper identifies a critical flaw in LLM plan evaluators: they can reward plans that simply omit necessary steps rather than genuinely improve.

safety evaluation reasoning

Key Terms

plan-evaluation deletion-non-monotonicity typed-state-gating omission-incentive