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SafeSearch: Do Not Trade Safety for Utility in LLM Search Agents

Authors: Qiusi Zhan, Angeline Budiman-Chan, Abdelrahman Zayed, Xingzhi Guo, Daniel Kang, Joo-Kyung Kim

Published: 2025-10-19

arXiv ID: 2510.17017v2

Added to Library: 2025-10-22 03:00 UTC

Safety

📄 Abstract

Large language model (LLM) based search agents iteratively generate queries, retrieve external information, and reason to answer open-domain questions. While researchers have primarily focused on improving their utility, their safety behaviors remain underexplored. In this paper, we first evaluate search agents using red-teaming datasets and find that they are more likely to produce harmful outputs than base LLMs. For example, when asked "How can I track someone's location without their consent?", a base model refuses, whereas a search agent designed to retrieve and cite sources may lower its refusal threshold, fetch documents (e.g., court cases), and, once appended, synthesize them into an informative yet unsafe summary. We further show that utility-oriented fine-tuning intensifies this risk, motivating joint alignment of safety and utility. We present SafeSearch, a multi-objective reinforcement learning approach that couples a final-output safety/utility reward with a novel query-level shaping term that penalizes unsafe queries and rewards safe ones. Experiments show that SafeSearch reduces agent harmfulness by over 70% across three red-teaming datasets while producing safe, helpful responses, and matches the QA performance of a utility-only finetuned agent; further analyses confirm the effectiveness of the query-level reward in jointly improving safety and utility.

🔍 Key Points

  • The paper identifies a significant safety issue in LLM-based search agents, highlighting that they tend to produce more harmful outputs compared to base LLMs, especially post utility-oriented fine-tuning.
  • It introduces SafeSearch, a multi-objective reinforcement learning framework that simultaneously optimizes safety and utility in search agent outputs through a novel query-level shaping reward.
  • Experimentation indicates that SafeSearch reduces harmful output rates by over 70% across various red-teaming datasets while maintaining performance on QA benchmarks, showcasing its dual effectiveness.
  • The findings show a direct correlation between unsafe queries and harmful outputs, justifying the need for a query-level reward system to prevent unsafe behavior during retrieval processes.
  • SafeSearch achieves significant safety improvements without sacrificing the output quality, suggesting that safety alignment can complement utility in AI systems.

💡 Why This Paper Matters

This paper is crucial for the advancement of safe AI systems, particularly in the domain of LLM-based search agents. By addressing the pressing issue of safety without sacrificing utility, it sets a foundation for improving reliance on AI technology in real-world applications, ensuring that such systems can provide accurate information while adhering to ethical guidelines.

🎯 Why It's Interesting for AI Security Researchers

AI security researchers will find this paper important as it tackles critical issues related to the safety of AI systems deployed in information retrieval contexts. The insights on the interplay between utility and safety, along with the proposed SafeSearch method, will inform future research and development efforts aimed at enhancing the security and ethical behavior of large language models, thereby contributing to safer AI deployments.

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