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A Deterministic Replacement for LLM-as-Judge in Stateful Agent Evaluation (arxiv.org)
4 points by jflynt76 92 days ago | hide | past | pdf | discuss on HN

In plain words: Instead of an AI judge rating an answer, GroundEval checks the agent's search, fetch, and citation trail against what evidence was allowed then. Two AI judges rated a plausible answer highly, but the agent never fetched the artifact behind it, GroundEval scored it 0.000.

Abstract · GroundEval: A Deterministic Replacement for LLM-as-Judge in Stateful Agent Evaluation

Before letting an agent operate over real context, can you prove it used the right evidence? GroundEval turns that question into a deterministic test of what the agent searched, fetched, cited, and was permitted to access. In one case study, two frontier LLM judges scored a plausible agent response 0.85 and higher. But the trace told a different story: the agent had never retrieved the artifact its answer depended on, yielding a GroundEval score of 0.000. We introduce GroundEval, a judge-free framework for evaluating agents against grounded, time-bounded, and access-controlled evidence. GroundEval uses a domain configuration to generate questions, lets the agent choose how to answer, and then scores both the final answer and the recorded trajectory that produced it. The benchmark targets three failures that LLM-as-judge evaluation struggles to detect: whether an agent checked before claiming absence, reasoned only from evidence available to the actor at the relevant time, and used the correct causal mechanism rather than a plausible one. These correspond to three tracks: Silence, Perspective, and Counterfactual. GroundEval exposes when plausible answers rest on invalid evidence paths, and produces structured per-question diagnostics that pair tool activity with the agent's turn-level narration, making each score inspectable rather than merely reported. Our case studies suggest this failure mode is common rather than exceptional, one that final-answer and judge-based evaluation cannot detect by construction.

Jeffrey Flynt
arXiv:2606.22737 · cs.AI, cs.CL, cs.SE · submitted Jun 22, 2026 · updated Jul 2, 2026
abstract · pdf · html · Streamlined entry point into framework

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