Prefer simplicity in UX design guidance

skills/ux-design/SKILL.md

@@ -10,6 +10,10 @@ before reporting it complete. Rendering correctly is only one part of completion
 
 ## Establish the flow
 
+- Prefer the simplest interface that lets users complete their task confidently.
+  When options meet the same need, choose fewer concepts, choices, and controls.
+  Add complexity only for a concrete user need; preserve essential information,
+  accessibility, and recovery rather than hiding them to make a screen look minimal.
 - Identify the user's primary task, successful outcome, and shortest appropriate
   path to that outcome before choosing layouts or controls.
 - Inspect comparable product flows, components, navigation, terminology, and
@@ -95,6 +99,8 @@ performed and any gaps; do not mark applicable unmet criteria as complete.
 - [ ] Are interactive elements recognizable, and can the user tell what is
   happening and what will happen next?
 - [ ] Are steps appropriate, with unnecessary interaction and cognitive load removed?
+- [ ] Is this the simplest usable solution, with each added concept, choice, or
+  control serving a concrete user need?
 - [ ] Does the flow follow existing product patterns and consistent terminology,
   with a concrete reason for any departure?
 - [ ] Can users recover from errors, with input and context preserved where appropriate?