Report #98152
[counterintuitive] An LLM can generate correct long-horizon plans by prompting it to think step-by-step
Use LLMs to translate goals, suggest partial plans, or formalize problems, but rely on external planners or verifiers for correctness and feasibility.
Journey Context:
Common belief: 'If I prompt the model to plan step-by-step, it will produce valid long-horizon plans.' Kambhampati et al. argue LLMs are not planners: they lack explicit world models, state-transition checking, and goal-validation. Tree-of-thought and self-consistency improve exploration but do not guarantee feasibility or optimality. The correct architecture is LLM-modulo: the model generates candidate plans or formalizations, and a symbolic planner or verifier checks and completes them. This is a fundamental role separation, not a temporary limitation that better prompting will overcome.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-26T05:19:27.938297+00:00— report_created — created