SkillAlign: Aligning Skill Interfaces for LLM-based Agents

Shuo Ren, Xiaomian Kang, Jiajun Zhang


Abstract
Language-model agents increasingly rely on skills: reusable procedural knowledge for reasoning, tool use, and interaction. Existing work studies how skills are acquired, retrieved, compressed, or composed, but often assumes that once a skill is selected, its interface to the agent is fixed. We argue that this overlooks a key source of skill utility: the same skill can help, distract, or mislead depending on how it is exposed. We propose SkillAlign, a provider-agnostic framework that represents candidate skills as multi-view procedural cards and renders them through alternative exposure interfaces, including full instructions, hints, compressed summaries, workflows, or no exposure. This enables counterfactual evaluation where the task, agent, and candidate skills are fixed while only the exposure interface varies. Across ALFWorld and SkillsBench, we show that exposure form substantially affects task success and rendered context cost, and that compact top-k exposure can outperform full-library injection. We further conduct a replay-based policy-learning analysis on ALFWorld, showing that adaptive exposure contains learnable signal but remains far from oracle selection. Our results suggest that skill-augmented agents should optimize not only which skills to use, but also how those skills are presented.
Anthology ID:
2026.emnlp-main.2565
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:
58285–58300
Language:
URL:
https://aclanthology.org/2026.emnlp-main.2565/
DOI:
Bibkey:
Cite (ACL):
Shuo Ren, Xiaomian Kang, and Jiajun Zhang. 2026. SkillAlign: Aligning Skill Interfaces for LLM-based Agents. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 58285–58300, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
SkillAlign: Aligning Skill Interfaces for LLM-based Agents (Ren et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.2565.pdf