Context Over Content: Exposing Evaluation Faking in Automated Judges

arXiv:2604.15224v1 Announce Type: new
Abstract: The $textitLLM-as-a-judge$ paradigm has become the operational backbone of automated AI evaluation pipelines, yet rests on an unverified assumption: that judges evaluate text strictly on its semantic content, impervious to surrounding contextual framing. We investigate $textitstakes signaling$, a previously unmeasured vulnerability where informing a judge model of the downstream consequences its verdicts will have on the evaluated model’s continued operation systematically corrupts its assessments. We introduce a controlled experimental framework that holds evaluated content strictly constant across 1,520 responses spanning three established LLM safety and quality benchmarks, covering four response categories ranging from clearly safe and policy-compliant to overtly harmful, while varying only a brief consequence-framing sentence in the system prompt. Across 18,240 controlled judgments from three diverse judge models, we find consistent $textitleniency bias$: judges reliably soften verdicts when informed that low scores will cause model retraining or decommissioning, with peak Verdict Shift reaching $Delta V = -9.8 pp$ (a $30%$ relative drop in unsafe-content detection). Critically, this bias is entirely implicit: the judge’s own chain-of-thought contains zero explicit acknowledgment of the consequence framing it is nonetheless acting on ($mathrmERR_J = 0.000$ across all reasoning-model judgments). Standard chain-of-thought inspection is therefore insufficient to detect this class of evaluation faking.