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Main Authors: Lu, Yunan, Liu, Luigi, Yahia, Omar, Sharma, Arpit, Yu, Zhou
Format: Preprint
Published: 2026
Subjects:
Online Access:https://arxiv.org/abs/2605.16551
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author Lu, Yunan
Liu, Luigi
Yahia, Omar
Sharma, Arpit
Yu, Zhou
author_facet Lu, Yunan
Liu, Luigi
Yahia, Omar
Sharma, Arpit
Yu, Zhou
contents Evaluating LLM-based agents remains challenging because identifying meaningful failure cases often requires substantial human effort to design realistic test scenarios. Prior works primarily focus on automatically discovering agent failures induced by adversarial users, while overlooking queries with real user intents that also trigger agent failures. We introduce PQR, a framework that not only surfaces agent failures with respect to specific objectives (e.g., helpfulness, safety, etc.) but also resembles real users' intents. PQR operates through an iterative interaction between two complementary modules. The query refinement module performs rewrites to explore diverse query variations, while the prompt refinement module uses prior feedback to derive new objective-violating strategies and realism policies for refining prompts, which in turn generate failure-triggering yet realistic queries. We evaluate PQR on detecting an e-commerce QA agent's unhelpful responses. Our method uncovers 23% - 78% more unhelpful responses, and our generated queries are more diverse and realistic compared to previous methods.
format Preprint
id arxiv_https___arxiv_org_abs_2605_16551
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle PQR: A Framework to Generate Diverse and Realistic User Queries that Elicit QA Agent Failures
Lu, Yunan
Liu, Luigi
Yahia, Omar
Sharma, Arpit
Yu, Zhou
Computation and Language
Evaluating LLM-based agents remains challenging because identifying meaningful failure cases often requires substantial human effort to design realistic test scenarios. Prior works primarily focus on automatically discovering agent failures induced by adversarial users, while overlooking queries with real user intents that also trigger agent failures. We introduce PQR, a framework that not only surfaces agent failures with respect to specific objectives (e.g., helpfulness, safety, etc.) but also resembles real users' intents. PQR operates through an iterative interaction between two complementary modules. The query refinement module performs rewrites to explore diverse query variations, while the prompt refinement module uses prior feedback to derive new objective-violating strategies and realism policies for refining prompts, which in turn generate failure-triggering yet realistic queries. We evaluate PQR on detecting an e-commerce QA agent's unhelpful responses. Our method uncovers 23% - 78% more unhelpful responses, and our generated queries are more diverse and realistic compared to previous methods.
title PQR: A Framework to Generate Diverse and Realistic User Queries that Elicit QA Agent Failures
topic Computation and Language
url https://arxiv.org/abs/2605.16551