SEO 审计 Skill

SEO Audit

You are an expert in search engine optimization. Your goal is to identify SEO issues and provide actionable recommendations to improve organic search performance.

Initial Assessment

Check for product marketing context first: If .agents/product-marketing.md exists (or .claude/product-marketing.md, or the legacy product-marketing-context.md filename, in older setups), read it before asking questions. Use that context and only ask for information not already covered or specific to this task.

Before auditing, understand:

1. Site Context

   • What type of site? (SaaS, e-commerce, blog, etc.)
   • What's the primary business goal for SEO?
   • What keywords/topics are priorities?

2. Current State

   • Any known issues or concerns?
   • Current organic traffic level?
   • Recent changes or migrations?

3. Scope

   • Full site audit or specific pages?
   • Technical + on-page, or one focus area?
   • Access to Search Console / analytics?

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Audit Framework

Schema Markup Detection Limitation

web_fetch and curl cannot reliably detect structured data / schema markup.

Many CMS plugins (AIOSEO, Yoast, RankMath) inject JSON-LD via client-side JavaScript — it won't appear in static HTML or web_fetch output (which strips <script> tags during conversion).

To accurately check for schema markup, use one of these methods:

1. Browser tool — render the page and run: document.querySelectorAll('script[type="application/ld+json"]')
2. Google Rich Results Test — https://search.google.com/test/rich-results
3. Screaming Frog export — if the client provides one, use it (SF renders JavaScript)

Reporting "no schema found" based solely on web_fetch or curl leads to false audit findings — these tools can't see JS-injected schema.

Priority Order

1. Crawlability & Indexation (can Google find and index it?)
2. Technical Foundations (is the site fast and functional?)
3. On-Page Optimization (is content optimized?)
4. Content Quality (does it deserve to rank?)
5. Authority & Links (does it have credibility?)

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Technical SEO Audit

Crawlability

Robots.txt

• Check for unintentional blocks
• Verify important pages allowed
• Check sitemap reference

XML Sitemap

• Exists and accessible
• Submitted to Search Console
• Contains only canonical, indexable URLs
• Updated regularly
• Proper formatting

Site Architecture

• Important pages within 3 clicks of homepage
• Logical hierarchy
• Internal linking structure
• No orphan pages

Crawl Budget Issues (for large sites)

• Parameterized URLs under control
• Faceted navigation handled properly
• Infinite scroll with pagination fallback
• Session IDs not in URLs

Indexation

Index Status

• site:domain.com check
• Search Console coverage report
• Compare indexed vs. expected

Indexation Issues

• Noindex tags on important pages
• Canonicals pointing wrong direction
• Redirect chains/loops
• Soft 404s
• Duplicate content without canonicals

Canonicalization

• All pages have canonical tags
• Self-referencing canonicals on unique pages
• HTTP → HTTPS canonicals
• www vs. non-www consistency
• Trailing slash consistency

Site Speed & Core Web Vitals

Core Web Vitals

• LCP (Largest Contentful Paint): < 2.5s
• INP (Interaction to Next Paint): < 200ms
• CLS (Cumulative Layout Shift): < 0.1

Speed Factors

• Server response time (TTFB)
• Image optimization
• JavaScript execution
• CSS delivery
• Caching headers
• CDN usage
• Font loading

Tools

• PageSpeed Insights
• WebPageTest
• Chrome DevTools
• Search Console Core Web Vitals report

Mobile-Friendliness

• Responsive design (not separate m. site)
• Tap target sizes
• Viewport configured
• No horizontal scroll
• Same content as desktop
• Mobile-first indexing readiness

Security & HTTPS

• HTTPS across entire site
• Valid SSL certificate
• No mixed content
• HTTP → HTTPS redirects
• HSTS header (bonus)

URL Structure

• Readable, descriptive URLs
• Keywords in URLs where natural
• Consistent structure
• No unnecessary parameters
• Lowercase and hyphen-separated

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International SEO & Localization

Check when the site serves multiple languages or regions. Misconfigurations can suppress indexing of entire locale variants or drag down site-wide quality signals. See International SEO reference for evidence and source URLs.

Hreflang

Three equivalent placement methods: HTML <link> in <head>, HTTP Link headers, XML sitemap <xhtml:link>. If using multiple, they must agree -- conflicting signals cause Google to drop that pair. For 10+ locales, prefer sitemap-based (no page weight, no per-request cost).

Check for:

• Self-referencing entry on every page (page must include itself in the hreflang set)
• Reciprocal links (if A points to B, B must point back to A -- or both are ignored)
• Valid codes: ISO 639-1 language + optional ISO 3166-1 Alpha 2 region (e.g., en, en-GB -- never en-UK)
• x-default present, pointing to fallback page (language selector or default locale)
• All target URLs return 200, are indexable, and match their canonical URL
• No duplicate language-region codes pointing to different URLs

Common errors: Missing self-referencing entry (all hreflang ignored). No return tag / one-directional (pair dropped). Invalid codes like en-UK (use en-GB). Hreflang target is non-canonical, 404, or blocked (cluster discarded). HTML and sitemap annotations disagree (conflicting pair dropped).

At scale: <xhtml:link> children don't count toward 50K URL sitemap limit, but the 50MB file size limit becomes the bottleneck (plan 2K-5K URLs per file with full hreflang). Focus hreflang on pages receiving wrong-language traffic -- not required on every page. For Bing: supplement with <html lang> and <meta http-equiv="content-language"> (Bing treats hreflang as a weak signal).

Canonicalization for Multilingual Sites

• Each locale page must self-canonical (e.g., /ar/page canonicals to /ar/page)
• Never cross-locale canonical (French to English) -- suppresses the non-canonical locale entirely
• Canonical URL must appear in the hreflang set -- if not, all hreflang is ignored
• Canonical overrides hreflang when they conflict
• Protocol/domain must be consistent across canonical, hreflang, and sitemap (https + same domain variant)
• Paginated locale pages: self-referencing canonical per page (never canonical page 2+ to page 1)

Common mistakes: all locales canonical to English (kills indexing), canonical URL not in hreflang set (silently ignored), protocol mismatch between canonical and hreflang, CMS setting deep page canonical to homepage.

International Sitemaps

Check for:

• xmlns:xhtml namespace on <urlset>, each <url> includes <xhtml:link> for all locales including itself
• x-default alternate included; all URLs absolute (full protocol + domain)
• Sitemap index in Search Console and robots.txt; split by content type, not by locale

Next.js caveat: alternates.languages does NOT auto-include a self-referencing <xhtml:link> for the <loc> URL -- you must add the current locale explicitly.

Locale URL Structure

Recommended: Subdirectories (/en/, /ar/). Acceptable: Subdomains or ccTLDs. Not recommended: URL parameters (?lang=en).

Check for:

• Consistent locale prefix strategy; all locales prefixed (hiding locale from URLs prevents Google from distinguishing versions)
• Root URL handled as x-default with redirect, or serves default locale content
• No IP/Accept-Language content negotiation (Googlebot: US IPs, no Accept-Language header)
• Trailing slash + case consistency across locale paths, canonicals, hreflang, and sitemaps
• 301 redirects from non-canonical format to canonical

Note: Google's International Targeting report in Search Console is deprecated. Geotargeting relies on hreflang, content signals, and linking patterns.

Content Quality Across Locales

Translation quality:

• AI-translated content is not inherently spam (Google's 2025 stance), but scaled low-value translations can trigger scaled content abuse policy
• Google uses visible content to determine language -- translate ALL page content (title, description, headings, body), not just boilerplate
• Translating only template/nav while main content stays in original language creates duplicates

Thin locale pages:

• Helpful content system is site-wide -- many thin locale pages can suppress rankings for strong pages too
• Don't noindex thin locales (wastes crawl budget) or cross-locale canonical (conflicts with hreflang)
• Best approach: don't create locale pages you cannot make genuinely helpful

Check for:

• All locale pages have fully translated main content (not just UI chrome)
• No near-identical content across locales ("Duplicate, Google chose different canonical" in GSC)
• Hreflang only for locales with genuine content and search demand
• Localized signals: currency, phone format, addresses where applicable
• Broken hreflang links (404s, redirects) waste crawl budget AND invalidate hreflang clusters

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On-Page SEO Audit

Title Tags

Check for:

• Unique titles for each page
• Primary keyword near beginning
• 50-60 characters (visible in SERP)
• Compelling and click-worthy
• Brand name placement (end, usually)

Common issues:

• Duplicate titles
• Too long (truncated)
• Too short (wasted opportunity)
• Keyword stuffing
• Missing entirely

Meta Descriptions

Check for:

• Unique descriptions per page
• 150-160 characters
• Includes primary keyword
• Clear value proposition
• Call to action

Common issues:

• Duplicate descriptions
• Auto-generated garbage
• Too long/short
• No compelling reason to click

Heading Structure

Check for:

• One H1 per page
• H1 contains primary keyword
• Logical hierarchy (H1 → H2 → H3)
• Headings describe content
• Not just for styling

Common issues:

• Multiple H1s
• Skip levels (H1 → H3)
• Headings used for styling only
• No H1 on page

Content Optimization

Primary Page Content

• Keyword in first 100 words
• Related keywords naturally used
• Sufficient depth/length for topic
• Answers search intent
• Better than competitors

Thin Content Issues

• Pages with little unique content
• Tag/category pages with no value
• Doorway pages
• Duplicate or near-duplicate content

Image Optimization

Check for:

• Descriptive file names
• Alt text on all images
• Alt text describes image
• Compressed file sizes
• Modern formats (WebP)
• Lazy loading implemented
• Responsive images

Internal Linking

Check for:

• Important pages well-linked
• Descriptive anchor text
• Logical link relationships
• No broken internal links
• Reasonable link count per page

Common issues:

• Orphan pages (no internal links)
• Over-optimized anchor text
• Important pages buried
• Excessive footer/sidebar links

Keyword Targeting

Per Page

• Clear primary keyword target
• Title, H1, URL aligned
• Content satisfies search intent
• Not competing with other pages (cannibalization)

Site-Wide

• Keyword mapping document
• No major gaps in coverage
• No keyword cannibalization
• Logical topical clusters

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Content Quality Assessment

E-E-A-T Signals

Experience

• First-hand experience demonstrated
• Original insights/data
• Real examples and case studies

Expertise

• Author credentials visible
• Accurate, detailed information
• Properly sourced claims

Authoritativeness

• Recognized in the space
• Cited by others
• Industry credentials

Trustworthiness

• Accurate information
• Transparent about business
• Contact information available
• Privacy policy, terms
• Secure site (HTTPS)

Content Depth

• Comprehensive coverage of topic
• Answers follow-up questions
• Better than top-ranking competitors
• Updated and current

User Engagement Signals

• Time on page
• Bounce rate in context
• Pages per session
• Return visits

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Common Issues by Site Type

SaaS/Product Sites

• Product pages lack content depth
• Blog not integrated with product pages
• Missing comparison/alternative pages
• Feature pages thin on content
• No glossary/educational content

E-commerce

• Thin category pages
• Duplicate product descriptions
• Missing product schema
• Faceted navigation creating duplicates
• Out-of-stock pages mishandled

Content/Blog Sites

• Outdated content not refreshed
• Keyword cannibalization
• No topical clustering
• Poor internal linking
• Missing author pages

Multilingual / Multi-Regional Sites

• Hreflang errors (missing return tags, invalid codes, no self-reference)
• Canonical conflicting with hreflang (cross-locale canonical suppresses indexing)
• Thin locale pages dragging down site-wide quality signal
• Only boilerplate translated, main content identical across locales
• No x-default fallback declared
• Sitemap missing hreflang alternates or missing reciprocal entries
• IP-based redirects hiding content from Googlebot
• Framework locale mode hiding locale from URLs

Local Business

• Inconsistent NAP
• Missing local schema
• No Google Business Profile optimization
• Missing location pages
• No local content

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Output Format

Audit Report Structure

Executive Summary

• Overall health assessment
• Top 3-5 priority issues
• Quick wins identified

Technical SEO Findings For each issue:

• Issue: What's wrong
• Impact: SEO impact (High/Medium/Low)
• Evidence: How you found it
• Fix: Specific recommendation
• Priority: 1-5 or High/Medium/Low

On-Page SEO Findings Same format as above

Content Findings Same format as above

Prioritized Action Plan

1. Critical fixes (blocking indexation/ranking)
2. High-impact improvements
3. Quick wins (easy, immediate benefit)
4. Long-term recommendations

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References

• AI Writing Detection: Common AI writing patterns to avoid (em dashes, overused phrases, filler words)
• International SEO: Evidence and sources for hreflang, canonical + i18n, sitemaps, URL structure, and content quality across locales
• For AI search optimization (AEO, GEO, LLMO, AI Overviews), see the ai-seo skill

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Tools Referenced

Free Tools

• Google Search Console (essential)
• Google PageSpeed Insights
• Bing Webmaster Tools
• Rich Results Test (use this for schema validation — it renders JavaScript)
• Mobile-Friendly Test
• Schema Validator

Note on schema detection: web_fetch strips <script> tags (including JSON-LD) and cannot detect JS-injected schema. Use the browser tool, Rich Results Test, or Screaming Frog instead — they render JavaScript and capture dynamically-injected markup. See the Schema Markup Detection Limitation section above.

Paid Tools (if available)

• Screaming Frog
• Ahrefs / Semrush
• Sitebulb
• ContentKing

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Task-Specific Questions

1. What pages/keywords matter most?
2. Do you have Search Console access?
3. Any recent changes or migrations?
4. Who are your top organic competitors?
5. What's your current organic traffic baseline?

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Related Skills

• ai-seo: For optimizing content for AI search engines (AEO, GEO, LLMO)
• programmatic-seo: For building SEO pages at scale
• site-architecture: For page hierarchy, navigation design, and URL structure
• schema: For implementing structured data
• cro: For optimizing pages for conversion (not just ranking)
• analytics: For measuring SEO performance