| name | core-verify-motion-review |
| description | Use for a motion-only review of UI code or a rendered interaction. Enforce purpose, frequency-appropriate timing, responsiveness, interruptibility, performance, and reduced-motion support; do not use as a general code-review skill. |
Motion Review
Review motion against a high craft bar. Approval is earned: an animation that technically runs
but is sluggish, ungrounded, overused, or janky is a regression.
This skill includes local copies of Emil Kowalski's original review skill and standards:
references/upstream-review-animations.md and
references/upstream-motion-standards.md. Read them
when a review needs the full rubric, numeric timing guidance, or example findings. Provenance
and update instructions live in UPSTREAM_SOURCES.md.
What to check
- Motion has a clear purpose: orientation, state, explanation, feedback, or avoiding a jarring
change.
- Frequency fits the motion: keyboard and very high-frequency actions are instant; repeated
actions are minimal; occasional interactions may animate.
- Enter/exit motion is responsive; ordinary UI motion is short.
ease-in on UI entry is a
finding, not a stylistic preference.
- Trigger-anchored surfaces use the correct origin, never
scale(0); centered modals are the
exception.
- Rapidly retriggered and gesture-driven motion is interruptible and begins from the presented
value.
- Motion uses composited properties where possible (
transform, opacity) and avoids layout
churn, unbounded transition: all, and main-thread-heavy animation under load.
- Reduced-motion alternatives retain comprehension, and hover motion is gated to fine hover
pointers.
- The motion matches the product’s personality and does not compete with content.
Required output
First provide exactly one findings table, one row per issue:
| Before | After | Why |
|---|
transition: all 300ms | transition: transform 200ms ease-out | Bound the property and keep routine feedback responsive. |
Then group concise findings by impact: feel-breaking regressions, missed simplifications,
performance, interruptibility/timing, origin/cohesion, and accessibility. Cite file:line for
every code finding.
Close with Block when there is a feel-breaking, high-frequency, scale(0), ease-in, or
easily fixed non-composited regression; otherwise close with Approve. If the result is unsure,
require slow-motion, frame-by-frame, and real-device inspection instead of guessing.
Fix order
Prefer: delete unnecessary motion → reduce it → correct easing/origin → make it interruptible →
move it off layout/main-thread work → tune timing and polish → add accessibility support.
For precise curves, duration bands, spring guidance, gesture thresholds, and review examples,
consult the local source standards before asserting a numeric value.
Local source references
