@inproceedings{chen-etal-2026-polished,
title = "Polished but Unresolved: Identifying Late-Stage Pressure States in Long-Horizon Tool-Use Agents",
author = "Chen, Haoyang and
Liu, Yi and
Shao, Jianzhi and
Xu, Xiaozhou and
Sun, Zhe and
Hu, Wei",
editor = "Lee, Hung-Yi and
Dev, Sunipa and
Li, Jessy and
Elliott, Desmond",
booktitle = "Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing",
month = oct,
year = "2026",
address = "Budapest, Hungary",
publisher = "Association for Computational Linguistics",
url = "https://aclanthology.org/2026.emnlp-main.1143/",
pages = "26189--26205",
ISBN = "979-8-89176-459-0",
abstract = "Long-horizon tool-use agents need not only to search and plan, but also to decide when to finalize. We study late-stage pressure states, in which an agent is biased toward submitting a final answer that appears complete and polished while key constraints remain unresolved. We first train a linear probe to show that this pressure state is identifiable from the agent{'}s hidden states. Then, we use activation interventions along this pressure direction and find that shifting the hidden states changes both the pressure score and whether the agent continues tool use or submits early. Through controlled context manipulations, we further see that the pressure is mitigated by constraint clarity and action mapping. Based on these findings, we propose Probe-Sensed Pressure Relief (PSPR), a plugin that applies lightweight pressure relief direction under moderate pressure and moves to structured organization under high pressure risk. Experiments on multiple long-horizon benchmarks show that our method consistently strengthens existing agent methods."
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%0 Conference Proceedings
%T Polished but Unresolved: Identifying Late-Stage Pressure States in Long-Horizon Tool-Use Agents
%A Chen, Haoyang
%A Liu, Yi
%A Shao, Jianzhi
%A Xu, Xiaozhou
%A Sun, Zhe
%A Hu, Wei
%Y Lee, Hung-Yi
%Y Dev, Sunipa
%Y Li, Jessy
%Y Elliott, Desmond
%S Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
%D 2026
%8 October
%I Association for Computational Linguistics
%C Budapest, Hungary
%@ 979-8-89176-459-0
%F chen-etal-2026-polished
%X Long-horizon tool-use agents need not only to search and plan, but also to decide when to finalize. We study late-stage pressure states, in which an agent is biased toward submitting a final answer that appears complete and polished while key constraints remain unresolved. We first train a linear probe to show that this pressure state is identifiable from the agent’s hidden states. Then, we use activation interventions along this pressure direction and find that shifting the hidden states changes both the pressure score and whether the agent continues tool use or submits early. Through controlled context manipulations, we further see that the pressure is mitigated by constraint clarity and action mapping. Based on these findings, we propose Probe-Sensed Pressure Relief (PSPR), a plugin that applies lightweight pressure relief direction under moderate pressure and moves to structured organization under high pressure risk. Experiments on multiple long-horizon benchmarks show that our method consistently strengthens existing agent methods.
%U https://aclanthology.org/2026.emnlp-main.1143/
%P 26189-26205
Markdown (Informal)
[Polished but Unresolved: Identifying Late-Stage Pressure States in Long-Horizon Tool-Use Agents](https://aclanthology.org/2026.emnlp-main.1143/) (Chen et al., EMNLP 2026)
ACL