UX First Principles

A reasoning skill, not a styling skill. Its job is to make interface decisions the way an experienced UI/UX professional would: by drawing on the established canons of design knowledge to choose what to build and why, leaving how it looks (tokens, color, type, brand) to execution skills that run alongside this one.

What this skill is for

Use this when a design decision is being made — not when colors are being picked. Good triggers:

• Laying out a screen, dashboard, form, or flow
• Choosing a navigation structure (tabs, drawer, sidebar, breadcrumb, wizard)
• Deciding how much to show at once vs. defer (disclosure, density)
• Grouping, ordering, and prioritizing elements on a surface
• Reviewing or critiquing an existing interface
• Resolving a "this feels cluttered / confusing / off" complaint into specific, fixable causes

If the task is purely "apply our color tokens" or "match the brand," that is execution — defer to the styling skill. This skill stops at the decision; it does not own the pixels.

The one rule that prevents the most damage