Andrew Yim
236be6c580
🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
2.7 KiB
2.7 KiB
name: seo-core-web-vitals
version: 1.0.0
description: Core Web Vitals analyzer for LCP, FID, CLS, INP performance metrics. Triggers: Core Web Vitals, page speed, LCP, CLS, FID, INP, performance.
allowed-tools: mcp__firecrawl__, mcp__perplexity__
SEO Core Web Vitals
Purpose
Analyze Core Web Vitals performance metrics and provide optimization recommendations.
Core Capabilities
- LCP - Largest Contentful Paint measurement
- FID/INP - Interactivity metrics
- CLS - Cumulative Layout Shift
- Recommendations - Optimization guidance
Metrics Thresholds
| Metric | Good | Needs Work | Poor |
|---|---|---|---|
| LCP | ≤2.5s | 2.5-4s | >4s |
| FID | ≤100ms | 100-300ms | >300ms |
| CLS | ≤0.1 | 0.1-0.25 | >0.25 |
| INP | ≤200ms | 200-500ms | >500ms |
Data Sources
Option 1: PageSpeed Insights (Recommended)
Use external tool and input results:
- Visit: https://pagespeed.web.dev/
- Enter URL, run test
- Provide scores to skill
Option 2: Research Best Practices
mcp__perplexity__search: "Core Web Vitals optimization [specific issue]"
Workflow
- Request PageSpeed Insights data from user
- Analyze provided metrics
- Identify failing metrics
- Research optimization strategies
- Provide prioritized recommendations
Common LCP Issues
| Cause | Fix |
|---|---|
| Slow server response | Improve TTFB, use CDN |
| Render-blocking resources | Defer non-critical CSS/JS |
| Slow resource load | Preload LCP image |
| Client-side rendering | Use SSR/SSG |
Common CLS Issues
| Cause | Fix |
|---|---|
| Images without dimensions | Add width/height attributes |
| Ads/embeds without space | Reserve space with CSS |
| Web fonts causing FOIT/FOUT | Use font-display: swap |
| Dynamic content injection | Reserve space, use transforms |
Common INP Issues
| Cause | Fix |
|---|---|
| Long JavaScript tasks | Break up tasks, use web workers |
| Large DOM size | Reduce DOM nodes |
| Heavy event handlers | Debounce, optimize listeners |
| Third-party scripts | Defer, lazy load |
Output Format
## Core Web Vitals: [URL]
### Scores
| Metric | Mobile | Desktop | Status |
|--------|--------|---------|--------|
| LCP | Xs | Xs | Good/Poor |
| FID | Xms | Xms | Good/Poor |
| CLS | X.XX | X.XX | Good/Poor |
| INP | Xms | Xms | Good/Poor |
### Overall Score
- Mobile: X/100
- Desktop: X/100
### Priority Fixes
1. [Highest impact recommendation]
2. [Second priority]
### Detailed Recommendations
[Per-metric optimization steps]
Limitations
- Requires external PageSpeed Insights data
- Lab data may differ from field data
- Some fixes require developer implementation
- Third-party scripts may be difficult to optimize