OPID does skill distillation for agentic RL using the agent's own completed trajectories as the skill source, so the supervision stays on-policy and matched to the current state distribution.
Hand-written or off-policy skill libraries drift from what the policy actually visits in multi-turn interaction, which is the gap it targets.
Skills are extracted in hindsight from finished rollouts and split into two levels: episode-level skills that capture global workflows and failure-avoidance rules, and step-level skills for local decisions, with a critical-first routing that distills the high-leverage ones back into the policy.
OPID: On-Policy Skill Distillation for Agentic Reinforcement Learning
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