Rubric definitions
Groundedness — Does the proposal demonstrate project-specific knowledge (real APIs, modules, conventions) vs. plausible-sounding generalities?
Insight — How unlikely is this idea to emerge from a 5-minute brainstorm by a regular contributor?
User Impact — How many real users would benefit and how meaningfully?
Spec Clarity — Could a maintainer turn this into a PR scope without back-and-forth?