arXiv AI

Monitoring Web Agents Without Internal Signals: Observable Trajectories and Key-Step Supervision

The paper introduces a method for monitoring web agents without relying on internal signals such as token logits. It proposes two observable trajectory representations—Macro features that capture cross‑step agent–environment interactions, and Micro features that assess consistency of intention, action, and expected state change via repeated black‑box queries. By labeling the first uncorrected critical error that leads to final failure as a key‑step boundary, the approach preserves valid early prefixes of failed trajectories and achieves risk prediction performance competitive with internal‑signal baselines across WebArena‑Lite and Online Mind2Web benchmarks.

arXiv Machine Learning
Oct 12

Can Failed Trajectories Reveal Where Agents Go Wrong? Agentic Failure Attribution Without Step-Level Labels

The paper introduces SOAP, a method for attributing failures in large language model agents without requiring step-level labels or a separate set of successful trajectories. SOAP builds a spectral reference space from LLM representations to assign base error scores to each step, then uses attention-based soft dependencies to propagate downstream error signals back to their likely upstream causes. Experiments demonstrate that SOAP outperforms existing baselines in accurately identifying decisive steps responsible for task failures.

By Do Nguyen-Thanh, Junlin Fang, Bing Li, Zhen Fang, Sean Du
arXiv AI
Aug 7

TRAJDEBUG: Tracing Error Lifecycle to Identify Critical Failures in Long-Horizon Agent Trajectories

arXiv:2608. 06346v1 Announce Type: new Abstract: LLM-based agentic systems have shown remarkable capabilities in complex domains, while suffering from cascading errors and difficulty in debugging.

By Yunjia Qi, Zehua Yin, Xintong Shi, Hao Peng, Songyuanyi Lu, Yixian Liu, Richeng Xuan, Yuhong Liu, Zhichao Hu, Xiaozhi Wang, Lei Hou, Bin Xu, Juanzi Li
arXiv AI
Aug 19

Beyond Suspicious Steps: Ontological Trust in Long-Horizon Agents

The paper introduces ontological trust, a task‑conditioned property of trajectory prefixes, and presents RGE, an online monitor that decomposes trust into Role, Goal, and Evidence. RGE uses LLMs only for structured task and step representations, while trust updates and interventions are deterministic, producing a replayable and auditable trust trajectory. Evaluated on a cross‑domain corpus, RGE outperforms rule‑, judge‑, and shield‑style baselines, achieving over 93% Drift F1 and maintaining high benign coverage.

By An He, Yao Wang, Haibin Zhang
arXiv AI
Sep 11

Do Agents Know When They Succeed? Calibrating Agent Confidence from Internal Representations

The paper examines whether internal representations of agentic systems can better indicate task success than traditional confidence measures. It introduces two methods—Latent Trajectory Dynamics (LTD) and Action Representation Probe (ARP)—that analyze changes in residual-stream representations and action-level representations, respectively. Experiments on Bash, SQL, and Python benchmarks with Qwen and DeepSeek models show these methods outperform conventional surface-level and sequence-based calibration baselines, offering a zero‑overhead reliability monitor without prompt changes or multiple rollouts.

By Priyanka Mary Mammen, Emil Joswin, Srujananjali Medicherla
arXiv AI
Oct 27

Estimation of Propagated Risk in LLM-based Multi-Agent Systems

The paper introduces Interaction-Effect Propagation (IE-Prop), a model that estimates error risk in large language model (LLM) based multi‑agent systems by conditioning on whether upstream agents are correct or incorrect. IE‑Prop learns separate effects for each sender‑receiver interaction, combines them using the sender’s estimated error risk, and recursively propagates these risks through the execution graph. Experiments on three architectures and benchmarks show that IE‑Prop improves final‑node AUROC by about 0.05 points over baselines and that multi‑step risk tracking adds an additional 0.03 AUROC in sequential systems.

By Shreyan Ganguly, Souradeep Chattopadhyay, Qisai Liu, Soumik Sarkar
arXiv Machine Learning
Jul 30

Forecasting Trajectory-Level Safety Risks in Black-Box Multi-Turn Interactions

arXiv:2607. 26820v1 Announce Type: new Abstract: As large language models (LLMs) evolve from standalone assistants into autonomous agents, ensuring their safety requires shifting beyond pointwise risk assessment to understand how risks emerge and unfold over long-horizon trajectories.

By Shi Lin, Peng Qian, Dinghao Liu, Renjie Sun, Sifan Wu, Dezhang Kong, Chenpei Wang, Xun Wang