Design Motion Principles: Build Intentional Motion or Audit Existing Animation

Who It's For

Design Motion Principles is for people who want to add intentional motion to interactive components or review the quality of existing animation. The official description presents it as a motion and interaction design skill with two modes: build creates interactive components with purposeful motion, while audit reviews existing animations. The page explicitly names Claude Code, Cursor, Windsurf, and other AI coding assistants, but does not present that list as the only supported scope.

A better starting point is to have an interface or animation that can already be discussed and to be willing to let the coding assistant choose a mode based on your request. If the request is ambiguous, the skill asks clarifying questions before acting. It is not a general-purpose keyframe tool, and it does not provide a standalone editor separate from a coding assistant. People who only want to hand-write CSS transitions or do not plan to install Skills will get limited value from it.

Complete Your First Attempt in 3 Minutes

Prerequisites: the current coding assistant must be able to install Skills, and you should already have an animation or interaction available for review. The official page gives one installation command as the sole path:

npx skills add kylezantos/design-motion-principles

This command installs the skill in a Skills location that the current assistant can read. Do not look for a second installation entry in parallel.

For the first attempt, start with a verifiable audit instead of changing a component immediately. Use a clear request such as: “Please review this animation in audit mode first, without changing the business code.” The skill determines the mode from the request; if it finds the request ambiguous, it asks questions first, and you continue after answering them.

audit writes files and opens a browser, so it has side effects. Before proceeding, ask the assistant to confirm that the report will be written to motion-audits/, then generate it after you agree. A successful signal is that the directory contains the audit result and the page opens in a browser. The official page does not specify a report filename, scoring rules, or a required example repository; the evidence only establishes that it writes to motion-audits/ and opens the result in a browser.

Reference page: https://github.com/kylezantos/design-motion-principles

Use Cases

Case one: audit an existing animation. The official second mode is audit existing animations. Point out the interface or animation segment to inspect and let the skill enter audit mode. The result is written to motion-audits/ and opened in a browser so that you can compare it with the recommendations. The evidence does not list individual checklist items or say that code can be changed automatically; after reviewing the report, decide whether to start a separate build. If the directory already contains older reports, first make sure files you still need will not be overwritten.

Case two: add purposeful motion to an interactive component. The official first mode is build interactive components with purposeful motion. Once build is clearly the selected mode, describe the component's state changes and the intended motion, then have the assistant build it according to the skill. This changes component code and therefore has side effects; first ask the assistant to explain which files it will touch, then confirm before writing. The page provides no default easing table, duration formula, or framework restrictions, so the evidence ends at “use build mode to create interactive components with purposeful motion.”

Boundaries of Use

The capability is limited to two modes: build for motion components and audit for reviewing existing animations. The mode is inferred from the request; when the request is ambiguous, the skill asks first, so do not send mutually conflicting instructions at the same time. Installation recognizes only npx skills add kylezantos/design-motion-principles. Claude Code, Cursor, and Windsurf are named examples, while the page also says that other AI coding assistants can be used; this should not be read as an exclusive whitelist. audit always writes to motion-audits/ and opens a browser, and the official page does not describe a custom output path. build changes components, so when there is no file list, use the paths actually identified by the assistant. There is no information about uninstalling, rollback, or offline design tools.