Saved in:
Bibliographic Details
Main Authors: Ko, Dayoon, Kim, Jihyuk, Kim, Sohyeon, Park, Haeju, Lee, Dahyun, Kim, Gunhee, Lee, Moontae, Lee, Kyungjae
Format: Preprint
Published: 2026
Subjects:
Online Access:https://arxiv.org/abs/2602.07549
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866914313996861440
author Ko, Dayoon
Kim, Jihyuk
Kim, Sohyeon
Park, Haeju
Lee, Dahyun
Kim, Gunhee
Lee, Moontae
Lee, Kyungjae
author_facet Ko, Dayoon
Kim, Jihyuk
Kim, Sohyeon
Park, Haeju
Lee, Dahyun
Kim, Gunhee
Lee, Moontae
Lee, Kyungjae
contents Recent search agents leverage multi-turn reasoning and search tools to achieve strong performance on multi-hop and long-horizon benchmarks. Yet it remains unclear whether they reliably reason across all requirements by tracking, verifying, and maintaining multiple conditions in these questions. We study this capability under multi-constraint problems, where valid answers must satisfy several constraints simultaneously. We find that illusory completion frequently occurs, wherein agents believe tasks are complete despite unresolved or violated constraints, leading to underverified answers. To diagnose this behavior, we introduce the Epistemic Ledger, an evaluation framework that tracks evidential support and agents' beliefs for each constraint throughout multi-turn reasoning. Our analysis reveals four recurring failure patterns: bare assertions, overlooked refutations, stagnation, and premature exit. Motivated by these findings, we examine whether explicit constraint-state tracking during execution mitigates these failures via LiveLedger, an inference-time tracker. This simple intervention consistently improves performance, substantially reducing underverified answers (by up to 26.5%) and improving overall accuracy (by up to 11.6%) on multi-constraint problems.
format Preprint
id arxiv_https___arxiv_org_abs_2602_07549
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle When Is Enough Not Enough? Illusory Completion in Search Agents
Ko, Dayoon
Kim, Jihyuk
Kim, Sohyeon
Park, Haeju
Lee, Dahyun
Kim, Gunhee
Lee, Moontae
Lee, Kyungjae
Artificial Intelligence
Computation and Language
Recent search agents leverage multi-turn reasoning and search tools to achieve strong performance on multi-hop and long-horizon benchmarks. Yet it remains unclear whether they reliably reason across all requirements by tracking, verifying, and maintaining multiple conditions in these questions. We study this capability under multi-constraint problems, where valid answers must satisfy several constraints simultaneously. We find that illusory completion frequently occurs, wherein agents believe tasks are complete despite unresolved or violated constraints, leading to underverified answers. To diagnose this behavior, we introduce the Epistemic Ledger, an evaluation framework that tracks evidential support and agents' beliefs for each constraint throughout multi-turn reasoning. Our analysis reveals four recurring failure patterns: bare assertions, overlooked refutations, stagnation, and premature exit. Motivated by these findings, we examine whether explicit constraint-state tracking during execution mitigates these failures via LiveLedger, an inference-time tracker. This simple intervention consistently improves performance, substantially reducing underverified answers (by up to 26.5%) and improving overall accuracy (by up to 11.6%) on multi-constraint problems.
title When Is Enough Not Enough? Illusory Completion in Search Agents
topic Artificial Intelligence
Computation and Language
url https://arxiv.org/abs/2602.07549