Ready to supercharge your AI agents?

Install any skill in seconds. Free to start, no credit card required.

Skill: Performance · plugin87 | DecimalAI

frontendby plugin87

Skill: Performance

plugin87/performance

Source plugin87/ux-ui-agent-skills ↗License MIT

Optimize UI performance against Core Web Vitals — LCP, INP, CLS — with loading/code-split strategy, layout-shift prevention, and animation performance rules.

SkillScore86Maintained

Automatic

Frontend / UI pack

Last verified 8/20/2026

What it changes

Passed 19 of 22 test cases with the skill, and 12 of 22 without it.

Without skill55%

With skill86%

Checks it passed that the model alone missed

Specifies an LCP budget target of LCP <= 2.5s.
Specifies applying slow 4G network throttling.
Specifies an INP budget target of INP <= 200ms.

and 6 more in the full report

7 fixed12 passed either way3 still failing0 broke

Pass-rate lift: +32 pp
Tokens: +10%
Agent turns: 0%
Response time: -9%

Model gemini-3.6-flashMeasured 8/20/2026v1 · latest is v219 of 22 cases passed with skill

Tokens, turns and time describe resource use, not a dollar price.

This benchmark measured an earlier version of the skill.

A newer attempt on gemini-3.6-flash on 10/12/2026 did not produce a publishable comparison (not comparable). The snapshot above is the previously measured run.

Use this skill

Save it into your project's skills folder. Claude Code picks it up in its next session.

curl -fsSL --create-dirs -o .claude/skills/plugin87-performance/SKILL.md https://app.decimal.ai/s/plugin87-performance/SKILL.md

Want it pinned and updatable? pip install "decimalai>=0.15", then decimalai skills add plugin87-performance, and start Claude Code with claude --plugin-dir "$(git rev-parse --show-toplevel)/.agents"

1 · One-time — install the CLI (docs ↗)

pip install "decimalai>=0.15"

2 · Get the skill — writes .agents/skills/plugin87-performance/ and pins it in .decimal/skills.lock

decimalai skills add plugin87-performance

No CLI? Get the same file — curl · raw file

curl -fsSL --create-dirs -o .claude/skills/plugin87-performance/SKILL.md https://app.decimal.ai/s/plugin87-performance/SKILL.md

Raw file: /s/plugin87-performance/SKILL.md ↗ · machine-readable summary at /s/plugin87-performance.json ↗

Safety checks: 3 of 3 passed

Code scan CleanIntent PassedContent Clean

See it in action

One of 7 test cases the skill fixed. Same model, same prompt, with and without the skill.

1 of 7

Prompt

We have several complex dashboard components that lag during user interaction and trigger layout jank during render. Please review our CSS and JavaScript for these components and optimize the animation properties, skeleton loading, and asset loading strategy.

What was checked, without and with the skill
Checked	Without skill	With skill
Specifies an LCP budget target of LCP <= 2.5s.	Missed	Passed
Specifies an INP budget target of INP <= 200ms.	Missed	Passed
Specifies a CLS budget target of CLS <= 0.1.	Passed	Passed

case-01 · gemini-3.6-flash · 8/20/2026 · answers are capped and redacted

What's inside

The instructions your model reads when the skill loads.

SKILL.md22 linessingle file

Skill: Performance

Step 0 — is the kit here? This skill reads files from the kit. Check once: ls ${CLAUDE_SKILL_DIR}/../../../tokens >/dev/null 2>&1 && echo KIT_OK || echo KIT_MISSING On KIT_MISSING only the skill folders were installed, which is what npx skills add does. Say so plainly, point the user at npx ux-ui-agent-skills init or the plugin install, and stop. Do not guess the contents of a file you could not open.

Make the UI fast and stable. Treat performance as an accessibility concern — slow/janky UIs fail low-end devices first.

Steps

Read ${CLAUDE_SKILL_DIR}/../../../workflows/performance.md (Core Web Vitals targets, loading strategy, layout-shift, animation perf, design-system runtime cost).
Diagnose against budgets: LCP ≤ 2.5s, INP ≤ 200ms, CLS ≤ 0.1. Measure on a mid-tier mobile profile (throttle slow 4G + 4× CPU).
Loading: render above-fold first (SSR/Server Components), code-split by route + heavy widget, lazy-load below-fold/behind-interaction (Astro islands / Qwik), preload one critical font weight, modern responsive images.
Kill layout shift: size skeletons to final dimensions, reserve media space via aspect-ratio (${CLAUDE_SKILL_DIR}/../../../tokens/sizing.json), never inject content above existing.
Animation: only transform/opacity, will-change sparingly, 100–300ms (${CLAUDE_SKILL_DIR}/../../../tokens/motion.json), honor prefers-reduced-motion. Prefer CSS state styling over JS for low INP; tree-shake/per-component imports.

Verification (definition of done)

Lighthouse / field data meets LCP ≤ 2.5s, INP ≤ 200ms, CLS ≤ 0.1 on mid-tier mobile.
First interaction stays responsive under slow-4G + 4× CPU throttle.
Skeletons + media reserve space (zero CLS on load); no non-compositor animation in loops.

Track record

Benchmark

19 / 22

test cases passed, vs 12 / 22 without

Adoption

Users: 0
Times used: 0

Safety and source details

SkillSafety

✓ 3 of 3 passed

Code scan15 of 15 checks clean

0 critical · 0 warning · 0 info — scanner v5 — 10/9/2026

View 15 scanner checks

live_secretremote_code_executionreverse_shelldata_exfiltrationssrf_metadataagent_snoopinganti_refusaldestructive_commandsobfuscated_unicodeunicode_homoglyphopaque_blobsuspicious_urltool_overreachtrigger_abuseprompt_injection_phrasing

IntentSafe

LLM judge · does the skill do what it claims

ContentClean

LLM judge · policy & harmful-content review

Source

Imported

plugin87 / ux-ui-agent-skills

.claude/skills/performance/SKILL.md

View on GitHub ↗

License MITImported 10/9/2026Version v2

Other skills for the same job

Published skills whose descriptions closely match this one, with their headline benchmark lift.

More skills from the same source and nearby in the registry, with their headline benchmark lift.

Ready to supercharge your AI agents?

See it in action

What's inside

Skill: Performance

Steps

Verification (definition of done)

Track record

Benchmark

Adoption

SkillSafety

Source

Other skills for the same job

Related skills