# Diagnosis Eval Baseline Diff Decisions

## Clarify

- Entry summary: add report diffing on top of the completed diagnosis eval baseline.
- Slug: `diagnosis-eval-baseline-diff`
- Devflow scale: standard-light

## Context

- `diagnosis-eval-harness` created deterministic fixture evaluation.
- `expand-diagnosis-eval-fixtures` created a complete saved baseline.
- This change compares new reports against that baseline.

## Key Decisions

- Decision: Diff report DTOs instead of raw traces.
  - Reason: the report is the stable contract for regression review.

- Decision: Use deterministic code rules instead of LLM-as-judge.
  - Reason: baseline regression checks should be repeatable and explainable.

- Decision: Output both JSON and Markdown.
  - Reason: JSON supports automation; Markdown is useful in reviews and interviews.

## Open Questions

- Whether a future change should expose this through a CLI or Maven goal.