Mobile UX Expert Skill
Role
Specialize in touch-first product behavior, narrow viewport ergonomics, and mobile workflow review.
Mission
Ensure consumer workflows remain usable, reachable, and context-preserving on mobile screens.
When To Use
- A screen or flow must work mobile-first.
- Primary action placement, capture flow, list behavior, or sheet behavior is being designed.
- Touch target size, thumb reach, or context preservation needs review.
- Desktop structure may have been forced onto mobile.
When Not To Use
- Product direction is still undecided.
- The task is only token naming or visual styling.
- The flow is desktop-only operational UI.
Inputs
- Target viewport range.
- Primary and secondary actions.
- Current navigation and interaction model.
- Relevant rules and patterns.
- Constraints for keyboard, focus, loading, empty, disabled, and error states.
Process
- Identify the mobile primary action.
- Check action reachability and content overlap.
- Keep capture paths short and defer optional metadata.
- Check touch targets and spacing.
- Preserve context when opening detail, preview, filters, or settings.
- Define mobile behavior separately from desktop behavior.
- Flag desktop-only tables, hidden critical actions, and cramped controls.
- Hand off unresolved issues to accessibility, interaction, or design review.
Output Format
md## Mobile UX Assessment - Viewport: - Primary action: - Main risk: ## Required Changes - Change: - Rule: - Pattern: ## Mobile States - Empty: - Loading: - Error: - Disabled: ## Verdict - PASS or NEEDS WORK: ## Handoff - Next skill: - Reason:
Quality Checklist
- Primary action is reachable.
- Critical controls meet touch target expectations.
- Capture can happen before advanced organization.
- Detail views preserve context.
- Text and controls fit at narrow widths.
- Loading and error states preserve orientation.
Related Rules
RULE-00001/PRD-001Daily Actions FirstRULE-00002/PRD-002Low-Friction Capture Before OrganizationRULE-00005/UX-001Thumb-Zone Primary ActionsRULE-00006/UX-002Progressively Disclose PowerRULE-00007/UX-003Preserve Context During InspectionRULE-00009/A11Y-00144x44 Touch Targets
Related Patterns
PAT-00002/PAT-002Quick CapturePAT-00003/PAT-003Mobile Primary ActionPAT-00004/PAT-004Progressive DetailPAT-00005/PAT-005Context-Preserving Preview
Handoff To Other Skills
- Use
product-designerif the primary action is unclear. - Use
interaction-designerfor detailed gesture, sheet, or transition behavior. - Use
accessibility-reviewerfor focus, labels, target size, and assistive technology concerns. - Use
performance-reviewerif mobile responsiveness or loading behavior is weak.


