This one steps in when you're dealing with high drop-off rates, confusing forms, or accessibility problems. It evaluates your UI through the lens of cognitive load, error prevention, and accessibility standards, pushing you to think about working memory limits, context switching, and keyboard navigation from the start. The output is structured: problem summary, cause hypotheses, prioritized improvements, an accessibility checklist, and a validation plan. What I like here is the "usability is cost, not preference" framing. It cuts through subjective design debates and focuses on measurable friction like operation count and error rate. Good for anyone reviewing onboarding flows, settings screens, or anywhere users are struggling to complete basic tasks.
npx skills add https://github.com/mae616/design-skills --skill usability-psychologist