Dynamic Dual-Granularity Skill Bank for Agentic RL

Songjun Tu, Chengdong Xu, Qichao Zhang, Yaocheng Zhang, Xiangyuan Lan, Linjing Li, Dong Li, Dongbin Zhao


Abstract
Agentic RL can benefit substantially from reusable experience, but existing skill-based methods mostly focus on trajectory-level guidance and provide limited support for the principled evaluation and maintenance of an evolving skill memory. We propose D2Skill, a dynamic dual-granularity skill bank for agentic RL that organizes reusable experience into task skills for high-level guidance and step skills for fine-grained decision support and error correction. D2Skill jointly trains the policy and skill bank through paired baseline and skill-injected rollouts under the same policy, using their performance gap to derive hindsight utility signals for both skill updating and policy optimization. Constructed from training-time trajectories, the skill bank is continuously expanded through reflection and maintained with utility-aware retrieval and pruning. Across ALFWorld, WebShop, and Search-Augmented QA, D2Skill consistently outperforms skill-free and skill-based baselines, remains effective with self-feedback, and transfers to unseen ALFWorld environments without test-time adaptation. Project Page: https://github.com/TU2021/D2Skill-AgenticRL
Anthology ID:
2026.emnlp-main.491
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
11294–11315
Language:
URL:
https://aclanthology.org/2026.emnlp-main.491/
DOI:
Bibkey:
Cite (ACL):
Songjun Tu, Chengdong Xu, Qichao Zhang, Yaocheng Zhang, Xiangyuan Lan, Linjing Li, Dong Li, and Dongbin Zhao. 2026. Dynamic Dual-Granularity Skill Bank for Agentic RL. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 11294–11315, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Dynamic Dual-Granularity Skill Bank for Agentic RL (Tu et al., EMNLP 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.emnlp-main.491.pdf