Agent skill

Accessible Motion Skill: Reduced Motion for Vestibular Safety

The accessible-motion skill teaches an AI coding agent to replace bounce with opacity changes, honor prefers-reduced-motion and check animations against three WCAG criteria.

Install
git clone https://github.com/dylantarre/animation-principles.git ~/.claude/plugins/animation-principles
View on GitHub

Stars, license and last push from GitHub. Install count as reported by the open skills directory.

What is the accessible-motion skill?

The accessible-motion skill from dylantarre's animation-principles repository adapts all 12 Disney principles for people with vestibular disorders or motion sensitivity. It says to avoid the 150 to 400ms window, offers instant or 500ms plus alternatives, honors prefers-reduced-motion, and lists WCAG 2.3.3, 2.2.2 and 2.3.1.

The accessible-motion skill sits at skills/01-by-domain/accessible-motion in dylantarre's animation-principles repository. Its SKILL.md applies Disney's 12 animation principles while protecting users with vestibular disorders, motion sensitivity and cognitive disabilities.

Its timing advice is specific. Skip the 150 to 400ms range, because that is fast enough to notice and slow enough to trigger symptoms. Choose instant at 0ms for snappy feedback, or extended at 500ms plus with minimal distance for gentle perception.

The swaps the skill makes

  • Squash and Stretch becomes an opacity or color change. A button darkens on press, and loading indicators pulse opacity instead of bouncing.
  • Anticipation becomes a static indicator. A loading state shows immediately and hover changes color instead of scaling.
  • Follow Through is eliminated. Elements reach the final state at once with no settling, bouncing or overshoot.
  • Arc allows straight movement only, if there is any movement at all.
  • Secondary Action is reduced to a single, clear feedback per interaction with no cascading or staggered animation.
  • Exaggeration is removed entirely.

Motion sorted by risk

  • Generally safe: subtle opacity fades, color transitions, scale changes under 5%, very slow movement at 500ms plus, and non-repeating animations.
  • Potentially harmful: parallax scrolling, background movement, zoom animations, spinning elements, fast repeated animations and moving areas larger than a quarter of the viewport.
  • Always avoid: auto-playing video backgrounds, infinite animations, flashing and rapid zoom in and out.

WCAG criteria and testing

The skill cites three WCAG 2.1 criteria: 2.3.3 Animation from Interactions at AAA, 2.2.2 Pause, Stop, Hide at A for moving content over 5 seconds, and 2.3.1 Three Flashes at A. Its test list starts with enabling reduced motion in OS settings.

Who the accessible-motion skill is for

Best for

  • Implementing reduced motion alternatives, vestibular-safe animations or WCAG compliance, which are the triggers in the skill description. For audits beyond motion, use the web accessibility skill.
  • Products where parallax, zoom or looping effects might harm users with motion sensitivity, alongside the wider checklist in fixing accessibility.
  • Teams who want a checklist the agent can run through when animating.

Not for

  • Playful or expressive motion. This skill favors clarity over personality and removes exaggeration entirely.
  • Performance tuning. The skill covers user comfort, and fixing motion performance covers performance.