Agent4Weakness: An Agentic Framework for In-Depth Model Weakness Discovery

Xuanliang Zhang, Chenghao Yang, Zhoufutu Wen, Dingzirui Wang, Ge Zhang, Xiying Zhao, Tianren Feng, Jianpeng Jiao, Jingkai Liu, Zaiyuan Wang, Zuo Wang, Wenya Wu, Zhou Huan, Jin Chen, Wenhao Huang, Qingfu Zhu, Wanxiang Che


Abstract
The rapid evolution of reasoning-intensive Large Language Models renders traditional metrics insufficient by masking fine-grained failures and implicit pathologies. Existing weakness discovery methods typically rely on rigid pipelines, yielding superficial insights that lack the diagnostic depth required for effective model improvement. To address this, we introduce Agent4Weakness, a multi-agent framework designed to replicate the rigorous workflow of human expert analysts. By integrating a Domain-Aware Memory for contextual reasoning with diagnostic evaluation skills and a Tool Abstraction mechanism for decouple data analysis, Agent4Weakness transforms raw evaluation traces into grounded, actionable reports. We validate our framework through an extensive study involving 104 models across 27 benchmarks. Experimental results demonstrate that Agent4Weakness produces diagnostic reports significantly superior to competitive baselines. Crucially, leveraging these insights for prompt guidance yields an average 3.7 point performance boost and establishes a closed-loop optimization framework.
Anthology ID:
2026.findings-emnlp.1511
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
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
32150–32186
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.1511/
DOI:
Bibkey:
Cite (ACL):
Xuanliang Zhang, Chenghao Yang, Zhoufutu Wen, Dingzirui Wang, Ge Zhang, Xiying Zhao, Tianren Feng, Jianpeng Jiao, Jingkai Liu, Zaiyuan Wang, Zuo Wang, Wenya Wu, Zhou Huan, Jin Chen, Wenhao Huang, Qingfu Zhu, and Wanxiang Che. 2026. Agent4Weakness: An Agentic Framework for In-Depth Model Weakness Discovery. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 32150–32186, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Agent4Weakness: An Agentic Framework for In-Depth Model Weakness Discovery (Zhang et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.1511.pdf