Skill or Skip? Learning Selective Skill Invocation in Agentic Tasks via Dual-Granularity Preference Learning

Chishui Chen, Jiaye Lin, Te Sun, Yi Yang, Junxi Wang, Cong Qin, Yangen Hu, Lu Pan, Ke Zeng


Abstract
Agent skills are callable procedural modules that provide reusable knowledge and execution policies for complex agentic tasks. However, existing methods mainly focus on selecting relevant skills or improving the skills themselves, while overlooking whether a relevant skill should actually be invoked at the current decision point. Unhelpful invocations may introduce irrelevant context and disrupt an otherwise correct execution process. To address this issue, we propose SelSkill, a dual-granularity preference-learning framework for selective skill invocation. SelSkill formulates skill use as a skill-or-skip decision, uses predictive uncertainty to prioritize candidate decision points, and constructs controlled invoke-skip preference pairs from shared trajectory prefixes. It further combines episode-level outcome preferences with step-level invocation preferences to capture both overall trajectory quality and the local effectiveness of skill invocation. On ALFWorld with Qwen3-8B, SelSkill improves task success by 10.9 points over the skill-enabled baseline and 7.8 over No-Skill, with 29.1-point higher execution precision. On BFCL, task success and execution precision improve by 5.7 and 29.5 points, respectively. Zero-shot results on Tau-bench and PopQA suggest partial transfer to unseen domains and skills.
Anthology ID:
2026.findings-emnlp.222
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
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SIGDAT
Publisher:
Association for Computational Linguistics
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Pages:
4665–4681
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URL:
https://aclanthology.org/2026.findings-emnlp.222/
DOI:
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Cite (ACL):
Chishui Chen, Jiaye Lin, Te Sun, Yi Yang, Junxi Wang, Cong Qin, Yangen Hu, Lu Pan, and Ke Zeng. 2026. Skill or Skip? Learning Selective Skill Invocation in Agentic Tasks via Dual-Granularity Preference Learning. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 4665–4681, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Skill or Skip? Learning Selective Skill Invocation in Agentic Tasks via Dual-Granularity Preference Learning (Chen et al., Findings 2026)
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https://aclanthology.org/2026.findings-emnlp.222.pdf