Multi-Field Tool Retrieval

Yichen Tang, Weihang Su, Min Zhang, Yiqun Liu, Qingyao Ai


Abstract
Integrating external tools enables Large Language Models (LLMs) to interact with real-world environments and solve complex tasks. Given the growing scale of available tools, effective tool retrieval is essential to mitigate constraints of LLMs’ context windows and ensure computational efficiency. Existing approaches typically treat tool retrieval as a traditional ad-hoc retrieval task, matching user queries against the entire raw tool documentation. In this paper, we identify three fundamental challenges that limit the effectiveness of this paradigm: (i) the incompleteness and structural inconsistency of tool documentation; (ii) the significant semantic and granular mismatch between user queries and technical tool documents; and, most importantly, (iii) the multi-aspect nature of tool utility, that involves distinct dimensions, such as functionality, input constraints, and output formats, varying in format and importance. To address these challenges, we introduce Multi-Field Tool Retrieval, a framework designed to align user intent with tool representations through fine-grained, multi-field modeling. Experimental results show that our framework achieves SOTA performance on five datasets and a mixed benchmark, exhibiting superior generalizability and robustness. We have open-sourced all the code and prompts in https://github.com/LittleDinoC/MFTR.
Anthology ID:
2026.emnlp-main.2212
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:
50316–50341
Language:
URL:
https://aclanthology.org/2026.emnlp-main.2212/
DOI:
Bibkey:
Cite (ACL):
Yichen Tang, Weihang Su, Min Zhang, Yiqun Liu, and Qingyao Ai. 2026. Multi-Field Tool Retrieval. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 50316–50341, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Multi-Field Tool Retrieval (Tang et al., EMNLP 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.emnlp-main.2212.pdf