AAMAS Conference 2026 Conference Paper
The Web Tool Trap: Understanding and Mitigating Over-Reliance in Browsing Agents
- Jiawei Guo
- Hongjie Nie
- Qianbo Zang
- Shu Yang
- Shuodi Liu
- Yiwei Ru
- Liuyu Xiang
- Di Wang
Large Language Model (LLM) agents that browse the web are increasingly important, but their effectiveness is hindered by imperfect integration of internal knowledge and external tools. We introduce BrowseBench and present the first systematic investigation into over-reliance patterns of browsing agents. Through controlled experiments, we identify three distinct failure modes: (1) Excessive Conservatism—unnecessary tool invocations for known information; (2) Over-trust in Web Sources—uncritical acceptance of retrieved content; and (3) Planning Deficiency—lack of query decomposition strategies. To address these, we propose three mitigation strategies: Direct Preference Optimization (DPO), Attention Refinement (AR), and Hierarchical Query Decomposition (HQD). Experiments demonstrate that our interventions significantly reduce over-reliance and enhance performance.