Runs a two-axis code review by diffing HEAD against whatever fixed point you give it (a branch, commit, or tag). One sub-agent checks if the changes follow your repo's documented standards (CONTRIBUTING.md, ADRs, style guides), the other checks if they match the spec from the originating issue or PRD. Both run in parallel so their contexts stay clean, then you get side-by-side reports. The split matters because code can nail the requirements but break conventions, or follow every standard while building the wrong thing. Use it when you want to review a PR or work-in-progress branch and care about both axes instead of just one.
npx skills add https://github.com/mattpocock/skills --skill review