arXiv AI

Before the Next Rollout: Diagnosing Skill Utility Shifts from Policy Updates

The paper investigates how policy updates can alter the marginal utility of unchanged skills in reinforcement learning agents. By analyzing changes in token preferences between skill and control conditions at fixed contexts from pre‑update rollouts, the authors develop readouts that combine interaction shifts with advantage estimates to diagnose utility changes. These readouts use only forward passes on existing rollouts, avoiding extra post‑update evaluations, and demonstrate that incorporating them into skill evolution improves downstream performance and reduces token consumption.

arXiv AI
Aug 20

SkillGate: Training In-Policy Skill Selection in Long-Horizon Agents

SkillGate is a method that trains agents to select the correct skill from a large slate during an episode by separating credit signals for skill selection and execution. It addresses the problem of selector credit starvation, where traditional outcome-rewarded RL fails to give sufficient credit to the skill-naming tokens, especially in long-horizon tasks. Experiments on five benchmarks show that SkillGate improves a 9B policy’s success rate from 40.8% to 53.2%, reduces exposure to misleading candidates, and requires fewer skill reads.

By Qingyao Li, Wenxiang Jiao, Shuai Shao, Kangning Zhang, Yuan Lu, Yi Guo, Weiwen Liu, Weinan Zhang, Yong Yu
arXiv Computation and Language
Oct 8

CoTrace: Data Recipes for Training Terminal Agents with Harness-Model Co-Evolution

arXiv:2610.10426v1 Announce Type: new Abstract: Terminal-agent capability depends jointly on model weights and the runtime harness that formats prompts, binds tools, and handles error recovery. Exist...

By Jixuan Chen, Jiaxin Zhang, Qinyuan Ye, Yada Pruksachatkun, Haoxiang Zhang, Jingming Zhuo, Yifan Zhang, Yutong Dai, Juntao Tan, Xiangyu Peng, Silvio Savarese, Zeyuan Chen, Lianhui Qin, Chien-Sheng Wu
arXiv AI
Sep 28

SkillEvoReg: Regularizing Agent Skill Evolution Against Overfitting

SkillEvoReg is a regularization framework designed to mitigate overfitting in language-model agents that evolve reusable external skills. It combines training-time skill dropout, complexity-aware local regularization, and causal counterexample validation to control skill-state growth and detect regressions. Applied across SkillOpt, SkillEvolBench, and ContinualSkillBench, it preserves downstream performance while improving transfer and later-stage evolution outcomes.

By Guanyu Nie, Fangzhou Zhu, Shixiong Kai, Xiongwei Han, Tao Zhong, Mingxuan Yuan
arXiv Machine Learning
Aug 10

SkillAligner: Treating Retrieved Skills as Adaptable Drafts at Execution Time

arXiv:2608. 06880v1 Announce Type: new Abstract: General-purpose skills promise reusable procedural knowledge for language agents, yet semantic relevance does not guarantee execution utility: a retrieved skill may encode assumptions that conflict with the current task, execution environment, or other retrieved skills.

By Qinfeng Li, Dalin He, Yuntai Bao, Ying Yang, Ruoxi Chen, Xinyan Yu, Lizhou Liang, Ge Su, Wenqi Zhang, Xuhong Zhang
arXiv AI
Jun 2

ReSkill: Reconciling Skill Creation with Policy Optimization in Agentic RL

arXiv:2606. 01619v1 Announce Type: new Abstract: Agentic reinforcement learning (RL) enables LLM agents to improve continuously from environment rewards, yet the resulting policies do not systematically accumulate reusable strategies that generalize across tasks.

By Zelin He, Haotian Lin, Boran Han, Wei Zhu, Haoyang Fang, Bernie Wang, Xuan Zhu, Runze Li, Matthew Reimherr
arXiv Machine Learning
Sep 14

MInTRL: Off-policy Intervention can boost On-policy RL

MInTRL (Minimal Intervention Reinforcement Learning) expands exploration in on-policy reinforcement learning by inserting sparse, local corrections into rollouts via a judge-intervention policy. These interventions replace erroneous suffixes and immediately return control to the main policy, allowing the agent to explore beyond its natural trajectory while maintaining on-policy data. The method uses a sequence-level advantage-regression objective, avoiding importance sampling, and demonstrates superior performance on math and code benchmarks compared to standard on-policy and off-policy baselines.

By Mingyu Chen, Yefan Tao, Gerald Friedland, Xuezhou Zhang, Chris Kong
arXiv AI
Oct 9

A Score Is Not a Policy: Measuring the Value of Adaptive Revision

The paper investigates how a higher‑level controller in a hierarchical latent reasoner decides whether to preserve or replace a lower‑level strategy. Experiments across different training seeds show that learned revision timing can produce varied policies, but none surpasses a fixed, forced timing policy on the same checkpoint. The study highlights that state‑dependent control can alter actions without improving task performance, and that timing decisions are order‑sensitive and largely captured by a strong fixed schedule.

By Ayushi Chadha