What problem does it solve? Before opening a pull request, developers often cannot clearly articulate what their branch actually changes relative to main, which behaviors differ, and what might break. This Skill produces a structured before/after explanation of a branch against the default branch, surfacing silent behavior changes, contract breaks, unupdated callers, and semantic conflicts with commits that landed on main meanwhile. ## Core Features & Use Cases - Behavioral change explanation: Groups the three-dot diff into behavioral changes (not per-file or per-commit), each carried down to an observable consequence, with before/after statements against main. - Risk pass: Detects silent behavior changes, contract breaks (API, schema, config, signatures), irreversible migrations, and callers left unupdated via repo-wide grep. - Collision detection: Lists commits that landed on the default branch since the merge-base touching the same files, distinguishing textual conflicts from semantic ones that merge cleanly but break behavior. - Use Case: Before opening a PR, ask what your feature branch does; you receive an eight-section report covering scope, changes, call-flow deltas, contracts and risk, collisions with main, gaps, and verification commands. ## Quick Start Ask the assistant to explain what your current branch changes compared to main before you open a pull request.
