APeB Benchmarks LLM Agent Personalization for Raw Queries

Garry Yang, Zizhe Chen, Xinru Chen, Yongqiang Chen, Jianxiang Wang, Deyu Zou, Linyi Ding, Jialiang Wu, Yunzhong He, Yu Gong, James Cheng, Huaixiao Tou· July 7, 2026 View original

Summary

This research introduces APeB, a new benchmark for evaluating the personalization capabilities of LLM-powered agents, particularly when handling underspecified user queries and noisy interaction histories. It reveals that current models struggle with intent and preference discovery, highlighting the need for dedicated history-utilization modules.

Researchers have developed a new benchmark, Agent Personalized Benchmark (APeB), specifically designed to test the personalization abilities of LLM-powered agents. Existing benchmarks often fall short by relying on pre-refined user queries or simplified interaction histories, failing to capture real-world challenges. APeB focuses on "personalized product search" (PPS), where agents must infer user intent and extract preferences from raw, underspecified queries and complex interaction histories. The study constructed APeB using action logs, pairing vague intents with rich historical data and candidate items. Evaluations of state-of-the-art LLMs using multi-step agent workflows revealed that while models handle explicit queries well, they struggle significantly with early-stage queries requiring the discovery of intent and preferences. A detailed analysis attributed this gap primarily to ineffective use of historical data. A simple history-aware query-refinement pipeline, VQRA, demonstrated consistent improvements, underscoring the necessity for specialized modules dedicated to leveraging interaction history in personalized agents.

Why it matters

For professionals building or deploying AI agents in customer-facing roles, this benchmark highlights a critical gap in personalization capabilities and points towards the need for more sophisticated history-aware designs to handle real-world, ambiguous user interactions effectively.

How to implement this in your domain

  1. 1Evaluate your current LLM agent's performance with underspecified user queries and complex interaction histories.
  2. 2Prioritize the development of dedicated modules for extracting and utilizing user preferences from historical data.
  3. 3Implement query-refinement pipelines that leverage interaction history to better infer latent user intent.
  4. 4Adopt multi-step agent workflows that allow for iterative intent and preference discovery.
  5. 5Benchmark personalization capabilities using diverse, real-world interaction logs rather than simplified datasets.

Who benefits

E-commerceCustomer ServiceMarketingRetailAI Development

Key takeaways

  • LLM agents struggle with personalization when queries are underspecified and histories are noisy.
  • Existing benchmarks often don't adequately test real-world personalization challenges.
  • Ineffective history utilization is a primary reason for poor personalization performance.
  • Dedicated history-aware modules and query refinement can significantly improve personalization.

Original post by Garry Yang, Zizhe Chen, Xinru Chen, Yongqiang Chen, Jianxiang Wang, Deyu Zou, Linyi Ding, Jialiang Wu, Yunzhong He, Yu Gong, James Cheng, Huaixiao Tou

"arXiv:2607.03162v1 Announce Type: new Abstract: LLM-powered agents struggle with personalization when users issue raw, underspecified queries. In this setting, agents must infer latent intent, extract preferences from noisy interaction histories, and select among competing altern…"

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Originally posted by Garry Yang, Zizhe Chen, Xinru Chen, Yongqiang Chen, Jianxiang Wang, Deyu Zou, Linyi Ding, Jialiang Wu, Yunzhong He, Yu Gong, James Cheng, Huaixiao Tou on X · view source

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