This covers the full spectrum of user feedback design, from immediate button states to system notifications. It breaks down four feedback types (immediate, confirmation, status, and notification) and gives you practical guidance on channels, hierarchy, and timing. The duration rules are sensible: toasts auto-dismiss in 3-5 seconds, errors stick around until resolved. What I like here is the emphasis on inline feedback over intrusive modals, and the "provide undo rather than 'Are you sure?'" principle. It's comprehensive without being prescriptive, giving you the building blocks to design feedback that actually keeps users informed instead of annoying them.
npx skills add https://github.com/owl-listener/designer-skills --skill feedback-patterns