arXiv AI

Agent Step Value: Auditing Evaluation-Channel Sensitivity in Black-Box Agent Traces

The paper introduces Agent Step Value (ASV), a metric that measures how step rewards change across different evaluation channels in black‑box agent traces. Using a matched 2x2 design on frozen PubMed question‑answering transitions, the authors find that cross‑channel gain signs disagree in 48.3% of cases, whereas same‑channel retries disagree only 0.3% of the time. The study shows that negative magnitudes in the generated‑view coordinate drive a positive direct mean and a negative generated‑view mean, and that source‑only generation can restore a positive mean direction on artifact‑bearing retrievals. The results demonstrate how ASV can localize channel sensitivity and test interventions before reusing step rewards.

arXiv Computation and Language
Oct 9

TRACE: Diagnosing Verifier Brittleness in Agentic Evaluation

The paper introduces TRACE, a protocol designed to diagnose whether changes in verifier scores for large language model agents reflect actual changes in agent behavior or merely alterations in the evaluation process. TRACE works by applying targeted changes to evaluation components, running paired experiments, and re‑scoring unchanged trajectories to isolate the source of score variation. Experiments on synthetic tasks and public benchmark tasks demonstrate that seemingly significant score shifts can often be attributed to evaluation artifacts, while TRACE can also detect genuine behavioral changes.

By Radhika Gaonkar
arXiv AI
Jun 30

SEVA: Self-Evolving Verification Agent with Process Reward for Fact Attribution

arXiv:2606. 29713v1 Announce Type: cross Abstract: Hallucination is the reliability bottleneck for LLM-based agents, and fact attribution verifiers are the last line of defense -- yet today's verifiers emit only opaque binary labels, leaving agents unable to self-correct and operators unable to audit.

By Aojie Yuan, Yi Nian, Haiyue Zhang, Zijian Su, Yue Zhao
arXiv AI
Oct 28

Monitor Accuracy Isn't the Answer: A Decision-Value Framework for Evaluating AI Agent Restart Monitors

The paper argues that classification accuracy alone is insufficient for evaluating AI agent restart monitors. It introduces a decision‑value framework with a decision‑sufficiency criterion and a finite‑sample decision audit to assess whether restarting an agent is beneficial. Empirical results on SymPy issues show that high accuracy can lead to both gains and losses, and that many traces fail to meet the audit’s certification threshold.

By Siddharth Jain, Venkat N. Vedam
arXiv Machine Learning
5d ago

What Standard Evaluations Hide About Detectors of Hijacked LLM Agents: Rare Attacks, Unseen Tools and Benchmark Transfer

The paper investigates how standard evaluations of detectors for hijacked large language model (LLM) agents may conceal important weaknesses. By auditing eleven evaluations on the AgentDrift and AgentDojo benchmarks, the authors show that detectors often perform poorly when faced with rare attacks, unseen tools, or data from a different benchmark, with precision dropping dramatically at low attack rates and rankings reversing as tool coverage falls. They also find that a released LLM action monitor, despite high AUROC on its own data, would still generate many false alerts when applied to a new benchmark. "whyItMatters":"The study highlights that current evaluation practices can give a misleading sense of detector reliability, underscoring the need for more robust, cross‑benchmark testing to ensure real‑world safety of LLM agents."

By Mahmoud Abbasi, Juan M. N\'u\~nez V., Amin Shahraki