An LLM judge is a model that scores or labels another model's output against a rubric, returning a pass, a score, or a pairwise preference the Arize guide. Copy review is a narrow case of that pattern: one model writes a headline, caption, or product blurb, and a second model checks it for accuracy, tone, unsupported claims, and policy fit.
A second judge is worth paying for because a single model is blind to its own habits. Judges vary widely by model and favor outputs that resemble their own, and LLM-as-judge setups are unstable on the subjective axes that matter most Prolific on annotator disagreement. A second model with a different training mix is a cheap way to catch the failure where the first model approves something fluent that makes a claim nobody can support.
Two consequences follow. The value of the second judge comes from independence, not raw capability, so the cheapest useful configuration is one strong model plus one different model, not one strong model twice. And the expensive part of the pipeline is usually the judge, not the writer, because the judge reads the full item, the brand rules, the source facts, and the policy text. That asymmetry is why routing decisions belong on the judge side.
The published survey literature on LLM-as-judge treats this as an evaluation-design problem: judges need a defined rubric, the task input, and any reference material required to assess the result the survey on LLM-as-a-judge. Copy review adds a routing question on top: which item, which judge strength.



