SEO Mastery Agent Skills

Comprehensive SEO optimization skill based on Google's official documentation. Provides integrated support for technical SEO, content optimization, structured data, Core Web Vitals, and site audits.

When to Use This Skill

Technical SEO

• Debugging crawl and indexing issues
• Configuring robots.txt / sitemap.xml
• Implementing canonical URLs / hreflang
• JavaScript SEO optimization
• Mobile-first optimization
• Server-side rendering (SSR) setup

Content SEO

• Meta tag optimization (title, description)
• Heading structure design (H1-H6)
• E-E-A-T (Experience, Expertise, Authoritativeness, Trustworthiness) strategies
• Search intent-aligned content design
• Internal linking strategy

Structured Data

• JSON-LD schema.org implementation
• Rich results support (FAQ, How-to, Article, Product, etc.)
• VideoObject, BroadcastEvent implementation
• BreadcrumbList configuration
• LocalBusiness / Organization setup

Core Web Vitals

• LCP (Largest Contentful Paint) optimization
• INP (Interaction to Next Paint) improvement
• CLS (Cumulative Layout Shift) fixes
• Performance monitoring and improvement

Site Audit

• Comprehensive SEO audit workflow
• Automated checklist generation
• Issue prioritization
• Improvement report creation

Quick Start

Basic Usage

# Request meta tag optimization
"Optimize the meta tags for this page"

# Generate structured data
"Add Article structured data to this blog post"

# Run site audit
"Perform an SEO audit on this site"

# Improve Core Web Vitals
"How can I improve LCP?"

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Technical SEO Checklist

Crawl Optimization

• robots.txt is properly configured
• XML sitemap exists and is submitted to Search Console
• Important pages are not set to noindex
• Crawl budget is not wasted
• No 404/5xx errors

Index Optimization

• Canonical URLs are correctly set
• Duplicate content is properly handled
• hreflang (for multilingual sites) is correct
• Mobile and desktop versions have the same content

Rendering Optimization

• JavaScript is properly rendered
• Critical content is included in HTML
• Lazy loading is properly implemented

---

Structured Data Templates

Article

{
  "@context": "https://schema.org",
  "@type": "Article",
  "headline": "Article title (max 110 characters recommended)",
  "description": "Article description",
  "image": [
    "https://example.com/photos/1x1/photo.jpg",
    "https://example.com/photos/4x3/photo.jpg",
    "https://example.com/photos/16x9/photo.jpg"
  ],
  "datePublished": "2025-01-01T08:00:00+00:00",
  "dateModified": "2025-01-15T10:30:00+00:00",
  "author": {
    "@type": "Person",
    "name": "Author Name",
    "url": "https://example.com/author/profile"
  },
  "publisher": {
    "@type": "Organization",
    "name": "Site Name",
    "logo": {
      "@type": "ImageObject",
      "url": "https://example.com/logo.png"
    }
  }
}

FAQ

{
  "@context": "https://schema.org",
  "@type": "FAQPage",
  "mainEntity": [
    {
      "@type": "Question",
      "name": "Question 1 text",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Answer 1 text"
      }
    },
    {
      "@type": "Question",
      "name": "Question 2 text",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Answer 2 text"
      }
    }
  ]
}

BreadcrumbList

{
  "@context": "https://schema.org",
  "@type": "BreadcrumbList",
  "itemListElement": [
    {
      "@type": "ListItem",
      "position": 1,
      "name": "Home",
      "item": "https://example.com/"
    },
    {
      "@type": "ListItem",
      "position": 2,
      "name": "Category",
      "item": "https://example.com/category/"
    },
    {
      "@type": "ListItem",
      "position": 3,
      "name": "Current Page"
    }
  ]
}

Product

{
  "@context": "https://schema.org",
  "@type": "Product",
  "name": "Product Name",
  "image": "https://example.com/product.jpg",
  "description": "Product description",
  "brand": {
    "@type": "Brand",
    "name": "Brand Name"
  },
  "offers": {
    "@type": "Offer",
    "url": "https://example.com/product",
    "priceCurrency": "USD",
    "price": "99.00",
    "availability": "https://schema.org/InStock",
    "seller": {
      "@type": "Organization",
      "name": "Seller Name"
    }
  },
  "aggregateRating": {
    "@type": "AggregateRating",
    "ratingValue": "4.5",
    "reviewCount": "128"
  }
}

LocalBusiness

{
  "@context": "https://schema.org",
  "@type": "LocalBusiness",
  "name": "Business Name",
  "image": "https://example.com/store.jpg",
  "address": {
    "@type": "PostalAddress",
    "streetAddress": "123 Main Street",
    "addressLocality": "New York",
    "addressRegion": "NY",
    "postalCode": "10001",
    "addressCountry": "US"
  },
  "geo": {
    "@type": "GeoCoordinates",
    "latitude": 40.7128,
    "longitude": -74.0060
  },
  "telephone": "+1-212-555-1234",
  "openingHoursSpecification": [
    {
      "@type": "OpeningHoursSpecification",
      "dayOfWeek": ["Monday", "Tuesday", "Wednesday", "Thursday", "Friday"],
      "opens": "09:00",
      "closes": "18:00"
    }
  ],
  "priceRange": "$$"
}

VideoObject

{
  "@context": "https://schema.org",
  "@type": "VideoObject",
  "name": "Video Title",
  "description": "Video description",
  "thumbnailUrl": [
    "https://example.com/thumb-1x1.jpg",
    "https://example.com/thumb-4x3.jpg",
    "https://example.com/thumb-16x9.jpg"
  ],
  "uploadDate": "2025-01-01T08:00:00+00:00",
  "duration": "PT5M30S",
  "contentUrl": "https://example.com/video.mp4",
  "embedUrl": "https://example.com/embed/video123",
  "interactionStatistic": {
    "@type": "InteractionCounter",
    "interactionType": { "@type": "WatchAction" },
    "userInteractionCount": 12345
  },
  "hasPart": [
    {
      "@type": "Clip",
      "name": "Introduction",
      "startOffset": 0,
      "endOffset": 30,
      "url": "https://example.com/video?t=0"
    },
    {
      "@type": "Clip",
      "name": "Main Content",
      "startOffset": 30,
      "endOffset": 300,
      "url": "https://example.com/video?t=30"
    }
  ]
}

---

Core Web Vitals Optimization Guide

LCP (Largest Contentful Paint) - Target: Under 2.5 seconds

Common Causes and Solutions:

Cause	Solution
Slow server response	CDN implementation, cache optimization, server upgrades
Render-blocking resources	Defer CSS/JS loading, inline Critical CSS
Slow image loading	Use WebP/AVIF, specify proper sizes, preload settings
Client-side rendering	Implement SSR/SSG, pre-render critical content

Example: Image Preloading

<link rel="preload" as="image" href="hero-image.webp" fetchpriority="high">

INP (Interaction to Next Paint) - Target: Under 200ms

Common Causes and Solutions:

Cause	Solution
Heavy JavaScript	Code splitting, remove unnecessary JS, defer execution
Long tasks	Split tasks (yield to main thread)
Large DOM size	Reduce DOM elements, implement virtual scrolling
Third-party scripts	Lazy load, review necessity

Example: Splitting Long Tasks

async function processLargeArray(items) {
  for (const item of items) {
    processItem(item);
    // Yield to main thread
    await new Promise(resolve => setTimeout(resolve, 0));
  }
}

CLS (Cumulative Layout Shift) - Target: Under 0.1

Common Causes and Solutions:

Cause	Solution
Images/videos without dimensions	Specify width/height attributes, use aspect-ratio CSS
Dynamically inserted content	Reserve space in advance, use skeleton UI
Web fonts (FOUT/FOIT)	font-display: swap, preload fonts
Ads/embeds	Pre-position fixed-size containers

Example: Image Aspect Ratio

<img src="image.jpg" width="800" height="600" alt="Description"
     style="aspect-ratio: 4/3; width: 100%; height: auto;">

---

E-E-A-T Optimization Checklist

Experience

• Provide content based on first-hand experience
• Include actual product usage reviews/photos
• Present case studies and examples

Expertise

• Author information page exists
• Author credentials/background are stated
• Content focuses on specialized field
• Provide accurate and up-to-date information

Authoritativeness

• Backlinks from trusted external sites
• Citations from industry bodies/experts
• Brand mentions earned
• Expert review/supervision

Trustworthiness

• HTTPS enabled
• Privacy policy exists
• Contact information is clear
• Company information/location is stated
• User reviews/ratings are displayed
• Sources are cited

---

Site Audit Workflow

Phase 1: Crawl Diagnosis

# Check robots.txt
curl -s https://example.com/robots.txt

# Check sitemap
curl -s https://example.com/sitemap.xml | head -50

# Index status (site: search)
# Search "site:example.com" on Google

Check Items:

1. Are important pages blocked by robots.txt?
2. Does sitemap.xml exist and include main pages?
3. Does index count match expectations?

Phase 2: Page-Level Diagnosis

HTML Head Elements:

# Extract meta information
curl -s https://example.com/ | grep -E '<title>|<meta name="description"|<link rel="canonical"'

Check Items:

1. Title tag (under 60 characters, includes keywords)
2. Meta description (under 160 characters)
3. Canonical URL
4. OGP / Twitter Card tags
5. Structured data presence

Phase 3: Performance Diagnosis

Lighthouse CLI:

npx lighthouse https://example.com --output=json --output-path=./report.json

Check Items:

1. Core Web Vitals scores
2. Accessibility score
3. SEO score
4. Performance improvement suggestions

Phase 4: Competitive Analysis

1. Content volume/structure of top-ranking sites
2. Backlink profiles
3. Structured data usage
4. Page speed comparison

Phase 5: Improvement Priority Matrix

Priority	Impact	Difficulty	Examples
Critical	High	Low	Remove noindex, fix 404s
High	High	Medium	Add structured data, optimize meta tags
Medium	Medium	Medium	Core Web Vitals improvements
Low	Low	High	Major site structure changes

---

Related Reference Files

This skill includes the following detailed documents:

File	Content	Use Case
technical-seo.md	robots.txt, sitemap, canonical, hreflang, etc.	Technical SEO configuration
content-seo.md	Meta tags, heading structure, content design	Content optimization
structured-data.md	All structured data type details	Rich results implementation
core-web-vitals.md	Detailed LCP/INP/CLS optimization	Performance improvement
audit-workflow.md	Audit procedures, tools, report formats	Site audit execution

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Recommended Tools

Google Official

• Google Search Console - Index status & search performance
• PageSpeed Insights - Core Web Vitals measurement
• Rich Results Test - Structured data validation
• Mobile-Friendly Test - Mobile compatibility check

CLI/Development Tools

• Lighthouse CLI - Performance auditing
• Screaming Frog - Large-scale site crawling
• ahrefs / SEMrush - Competitive & backlink analysis

---

Common Mistakes and Solutions

1. Keyword Stuffing

• Avoid: "SEO SEO SEO optimization SEO tools SEO company"
• Better: Use keywords naturally in context

2. Duplicate Content

• Avoid: www vs non-www, http vs https as separate URLs
• Better: Canonical settings, 301 redirects

3. Slow Image Loading

• Avoid: Large PNG/JPG files used as-is
• Better: WebP conversion, proper sizing, lazy loading

4. Structured Data Errors

• Avoid: Missing required fields, invalid formats
• Better: Pre-validate with Rich Results Test

5. Not Mobile-Friendly

• Avoid: Desktop-only, no touch support
• Better: Responsive design, adequate tap targets

---

Official Resources

• Google Search Central
• SEO Starter Guide
• Search Essentials
• Structured Data Documentation
• Core Web Vitals

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Changelog

• v1.0.0 (2025-01) - Initial release
  • Created based on Google's official SEO guides
  • Comprehensive technical SEO, content SEO, structured data coverage
  • Core Web Vitals (2024 INP-compliant version)
  • E-E-A-T optimization checklist added
  • Site audit workflow added