A rubric is a specification: it says what good and bad look like so that two reviewers reach the same verdict on the same output the Arize glossary. That solves the scoring problem. It does not solve the decision problem, because a set of dimension scores still leaves the team arguing about what the numbers mean.
The gap matters most for agents. A single user request can trigger dozens of internal steps, tool calls, and reasoning loops before producing a final answer, and a correct-looking answer can hide a broken process the LangChain framework. Google's practitioners describe the same trap as a "silent failure": an agent reports the right inventory number but references last year's report by mistake the Google Cloud guide. If your rubric scores those behaviors separately, you already have the raw material. The missing step is aggregation with weights and a pass bar.
There is a second reason to formalize the decision. Rubrics drift and so do raters. Research on examiner scoring found inter-rater reliability is negatively impacted when no formal or consistent rater training and rubric calibration is performed the ERIC study. The same calibration discipline applies to a go/no-go meeting: without a fixed rule written down in advance, your threshold moves to fit whoever is in the room.



