AEM: Adaptive Entropy Modulation for Multi-Turn Agentic Reinforcement Learning

Fuente: arXiv
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Main Authors: Zhao, Haotian, Zhou, Songlin, Zhang, Yuxin, Yau, Stephen S. -T., Zhang, Wenyu, Tian, Lun, Zhu, Tianshu, Huang, Yifeng, Zeng, Yucheng, Gu, Jingnan, Dong, Daxiang, Wu, Jianmin
Format: Preprint
Published: 2026
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author Zhao, Haotian
Zhou, Songlin
Zhang, Yuxin
Yau, Stephen S. -T.
Zhang, Wenyu
Tian, Lun
Zhu, Tianshu
Huang, Yifeng
Zeng, Yucheng
Gu, Jingnan
Dong, Daxiang
Wu, Jianmin
author_facet Zhao, Haotian
Zhou, Songlin
Zhang, Yuxin
Yau, Stephen S. -T.
Zhang, Wenyu
Tian, Lun
Zhu, Tianshu
Huang, Yifeng
Zeng, Yucheng
Gu, Jingnan
Dong, Daxiang
Wu, Jianmin
contents Reinforcement learning (RL) has substantially improved the ability of large language model (LLM) agents to interact with environments and solve multi-turn tasks. However, effective agentic RL remains challenging: sparse outcome-only rewards provide limited guidance for assigning credit to individual steps within long interaction trajectories. Existing approaches often introduce dense intermediate supervision, such as process reward models or auxiliary self-supervised signals, which increases supervision and tuning complexity and may limit generalization across tasks and domains. We present AEM, a supervision-free credit assignment method that adaptively modulates entropy dynamics during RL training to improve the exploration-exploitation trade-off. Since in agentic RL the environment is typically affected by a complete response, rather than an individual token, our analysis lifts entropy dynamics from the token level to the response level, aligning uncertainty estimation with the effective action granularity of LLM agents and reducing sensitivity to token-level sampling noise. We further show that entropy drift under natural-gradient updates is governed by the interaction between the sampled-response advantage and its relative surprisal. Motivated by this result, AEM derives a practical response-level uncertainty proxy and uses it to rescale advantages, leveraging the evolving balance between positive and negative samples to naturally transition from exploration to exploitation. Extensive experiments on ALFWorld, WebShop, and SWE-bench-Verified with models ranging from 1.5B to 32B demonstrate that AEM consistently improves strong RL baselines, including a +1.4\% gain when integrated into a state-of-the-art software-engineering RL training framework.
format Preprint
id arxiv_https___arxiv_org_abs_2605_00425
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle AEM: Adaptive Entropy Modulation for Multi-Turn Agentic Reinforcement Learning
Zhao, Haotian
Zhou, Songlin
Zhang, Yuxin
Yau, Stephen S. -T.
Zhang, Wenyu
Tian, Lun
Zhu, Tianshu
Huang, Yifeng
Zeng, Yucheng
Gu, Jingnan
Dong, Daxiang
Wu, Jianmin
Artificial Intelligence
cs.AI, cs.IT, cs.SE
Reinforcement learning (RL) has substantially improved the ability of large language model (LLM) agents to interact with environments and solve multi-turn tasks. However, effective agentic RL remains challenging: sparse outcome-only rewards provide limited guidance for assigning credit to individual steps within long interaction trajectories. Existing approaches often introduce dense intermediate supervision, such as process reward models or auxiliary self-supervised signals, which increases supervision and tuning complexity and may limit generalization across tasks and domains. We present AEM, a supervision-free credit assignment method that adaptively modulates entropy dynamics during RL training to improve the exploration-exploitation trade-off. Since in agentic RL the environment is typically affected by a complete response, rather than an individual token, our analysis lifts entropy dynamics from the token level to the response level, aligning uncertainty estimation with the effective action granularity of LLM agents and reducing sensitivity to token-level sampling noise. We further show that entropy drift under natural-gradient updates is governed by the interaction between the sampled-response advantage and its relative surprisal. Motivated by this result, AEM derives a practical response-level uncertainty proxy and uses it to rescale advantages, leveraging the evolving balance between positive and negative samples to naturally transition from exploration to exploitation. Extensive experiments on ALFWorld, WebShop, and SWE-bench-Verified with models ranging from 1.5B to 32B demonstrate that AEM consistently improves strong RL baselines, including a +1.4\% gain when integrated into a state-of-the-art software-engineering RL training framework.
title AEM: Adaptive Entropy Modulation for Multi-Turn Agentic Reinforcement Learning
topic Artificial Intelligence
cs.AI, cs.IT, cs.SE
url https://arxiv.org/abs/2605.00425