Guide · Agent skill
How to use the animation-performance agent skill
Updated · written with AI from the project's own documentation and checked against our catalogue data
The animation-performance skill is an agent skill, a set of instructions a compatible AI agent loads to carry out a specific task. Once it is installed, the agent reviews your stylesheets and components for animations that change layout properties such as width, height, top, left or margin, which can make motion stutter. This guide covers what the skill does, how to install it, how to ask for a review and what to check in the results.
Animation Performance Reviewthedaviddias/Front-End-Checklist · MIT Download the skill Quick start
- 1Download the ZIP. Get the animation-performance skill ZIP from this page.
- 2Unzip the folder. Extract the archive so you have an animation-performance folder containing SKILL.md and references/rule.md.
- 3Place the skill. Move the folder into ~/.claude/skills/ for personal use, or into .claude/skills/ inside your project.
- 4Or upload in the Claude apps. If you use the Claude apps, upload the skill under Settings → Capabilities → Skills instead.
- 5Ask for a review. Describe the stylesheets or components you want checked, in plain language, and mention animations or responsive behaviour.
- 6Verify the fixes. Test every proposed change in the rendered UI across breakpoints before you accept it.
What the animation-performance skill makes the agent do
The skill is built around one rule: animate transform and opacity rather than layout properties. The source explains that animating width, height, top, margin and similar properties runs the full browser rendering pipeline on every frame, on the main thread, where it competes with JavaScript. Animating transform and opacity skips layout and paint and runs on a separate GPU thread.
When the skill applies, the agent looks for CSS animations or transitions that change layout-triggering properties and flags them. It proposes switching position changes to translate() and size changes to scale(). It can also explain the browser rendering pipeline and how the GPU compositor works, and it checks reduced-motion preferences and will-change usage.
- Flags CSS animations and transitions that animate top, left, width, height or margin
- Proposes transform (translate, scale) and opacity as replacements
- Explains the rendering pipeline: Style, Layout, Paint, Composite
- Checks prefers-reduced-motion and will-change usage
Layout-triggering properties (avoid animating):
width, height, margin, padding, top, left, right, bottom,
border-width, font-size, display, position
Compositor-only properties (optimal for animation):
transform (translate, scale, rotate, skew)
opacity
filter (on composited layers)How do you install the animation-performance skill?
Download the skill's ZIP file from this page and unzip it. Then place the folder in one of two locations. For a personal setup that applies across your projects, use ~/.claude/skills/. For a single project, use the .claude/skills/ folder inside that project.
If you use the Claude apps instead, you can upload the skill under Settings → Capabilities → Skills rather than copying files by hand.
- Personal: ~/.claude/skills/
- Single project: .claude/skills/ inside the project folder
- Claude apps: Settings → Capabilities → Skills
How do you trigger the skill with a natural request?
You do not need a special command. Describe the task in plain language that mentions stylesheets, components, animations or responsive behaviour, and the agent can match the request to the skill's description. Naming the files or components you want reviewed makes the result more specific.
The skill's own description tells the agent to check the rendered layout across breakpoints and interaction states before proposing a fix, so mention breakpoints or hover and focus states if they matter to your review.
- Review the animations in src/components/Modal.css for layout properties
- Check our menu slide-in and card hover animations for jank and suggest fixes
- Review the responsive styles in styles/ for animations that move elements using top or left
- Explain why the sidebar animation stutters and how to fix it using transform
What should you check in the agent's results?
The skill asks the agent to flag exact selectors, declarations or breakpoints that break the rule. Read each flagged item against the rendered UI, since the skill is meant to be verified there. Visual behaviour can change when you swap a property, so confirm the animation still looks right at each breakpoint.
The skill's guidance does not cover canvas, WebGL or physics-based animation, so treat advice on those as possibly incomplete.
- Each flagged selector or declaration should name the layout property being animated
- Proposed fixes should use transform or opacity in place of the flagged property
- Confirm the reduced-motion and will-change notes apply to your code
What does the skill need, and what are the safety notes?
The skill lists no required prerequisites. It does not run scripts and does not use the network. Its files are SKILL.md, which holds the main instructions, and references/rule.md, which holds fuller implementation details and code examples.
Because the skill only reads and advises, it does not change your code on its own. Any rewrite you accept should still be tested in the rendered UI before release.
- Requires: nothing listed
- Runs scripts: no
- Uses network: no
- Files: SKILL.md and references/rule.md
What people use it for
- Reviewing a component library for hover and transition animations that use top, left or margin
- Checking a responsive navigation menu for layout-triggering slide-in effects
- Explaining to a junior developer why a loading spinner or card animation stutters
- Converting position-based animations to translate() and size-based ones to scale()
Frequently asked questions
Is the animation-performance skill free to use?
The skill is published under the MIT licence, as stated on this page. Check the licence file in the source repository for the full terms.
What do I need to run the animation-performance skill?
The skill lists no requirements. It does not run scripts and does not use the network, so you need an agent environment that can load skills and a project with CSS or JavaScript animations to review.
How do I install an agent skill from a ZIP file?
Download the ZIP, unzip it, and place the animation-performance folder in ~/.claude/skills/ for personal use or in .claude/skills/ within a project. In the Claude apps, you can instead upload it under Settings → Capabilities → Skills.
Why should I animate transform and opacity instead of top or width?
Animating transform and opacity skips layout and paint and runs on the GPU compositor thread. Animating top, left, width or height recalculates layout on every frame on the main thread, which can make motion stutter.
Does the skill work with canvas, WebGL or physics animations?
The guidance does not cover complex canvas, WebGL or physics-based animation, so advice for those may be incomplete. Verify any suggestions in the rendered UI.
Can the skill change my code automatically?
The skill flags issues and proposes fixes. Changes to visual behaviour should be tested in the rendered UI before you accept them.
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Our verdict
This skill suits front-end developers, teams reviewing UI code before release, and anyone learning why some CSS animations jank. It is less useful for projects with no CSS or JavaScript animation, or for canvas, WebGL and physics-based work, where its guidance is limited.
Download the skill