This is part of PostPlus AI's video editing workflow toolset, and it does exactly what it says: builds a structured catalog of your B-roll footage before you start cutting. You point it at your assets and get back a JSON inventory file, plus optional contact sheets and frame manifests if you need them. It's meant to sit at the front of the editing pipeline so you actually know what footage you have instead of scrubbing through files repeatedly. The 288 installs suggest the PostPlus video workflow has some traction, and having this kind of asset inventory as a separate, reusable skill makes sense if you're doing any volume of video work where B-roll management becomes a real problem.
npx skills add https://github.com/postplusai/postplus-skills --skill broll-catalog-builder