Report #101867
[counterintuitive] LLM generates invalid or suboptimal plans despite confident chain-of-thought reasoning
Use the LLM to translate goals or propose subplans, then validate plans with symbolic planners, SAT/SMT solvers, or executable simulators; never trust an autoregressive model to do combinatorial search on its own.
Journey Context:
Chain-of-thought makes planning look achievable, but autoregressive LLMs lack systematic backtracking and cannot reliably self-verify. Research on classical planning benchmarks shows autonomous LLM plan generation succeeds only a small fraction of the time. The right architecture is LLM-modulo: the model supplies knowledge, heuristic suggestions, and translations, while an external verifier or planner enforces correctness.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-07-07T05:34:51.135546+00:00— report_created — created