megastep/codex-skills
blog-seo-check
Post-writing SEO validation with pass/fail checklist covering title tag length and keyword placement, meta description quality, heading hierarchy and keyword density, internal/external link audit with anchor text analysis, canonical URL verification, Open Graph meta tags (og:title, og:description, og:image), Twitter Card validation, URL structure optimization, and image alt text presence. Produces prioritized fix list with specific recommendations. Use when user says "seo check", "check seo", "…
Marketing
Use judgment
Installs
13
Stars
5
Security
No audit
Freshness
Unknown
Updated
—
First seen Feb 26, 2026
Installation
Project
Global
Entire repo
Entire repo (global)
$
npx skills add megastep/codex-skills --skill blog-seo-check
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SKILL.md
Blog SEO Check -- Post-Writing Validation
Runs a comprehensive on-page SEO validation against a completed blog post and generates a pass/fail checklist with specific fixes for each failure. Designed to run after writing — catches issues before publishing.
Workflow
Step 1: Read Content
Read the target file and extract:
Frontmatter — title, description, date, lastUpdated, author, tags,
canonical, og:image, slug/URL
Heading structure — H1, H2, H3 hierarchy with full text
Links — All internal and external links with anchor text
Meta tags — OG tags, Twitter Card tags, canonical URL
Body content — Full text for keyword and structural analysis
If the user provides a URL instead of a file path, use WebFetch to retrieve the page and extract the relevant elements.
Step 2: Title Tag Validation
Check
Pass Criteria
Character count
40-60 characters (no truncation in SERPs)
Keyword placement
Primary keyword in first half of title
Power word
Contains at least one power word (e.g., Guide, Best, How, Why, Essential, Proven, Complete)
Truncation risk
No critical meaning lost if truncated at 60 chars
Uniqueness
Not generic — specific to the content
Step 3: Meta Description
Check
Pass Criteria
Character count
150-160 characters
Statistic included
Contains at least one specific number or data point
Value proposition
Ends with clear reader benefit or value proposition
Keyword presence
Primary keyword appears naturally (not stuffed)
No keyword stuffing
Keyword appears at most once
Call to action
Implies action (learn, discover, find out, see)
Step 4: Heading Hierarchy
Check
Pass Criteria
Single H1
Exactly one H1 tag (the title)
No skipped levels
H1 -> H2 -> H3, never H1 -> H3 or H2 -> H4
Keyword in headings
Primary keyword in 2-3 headings (natural, not forced)
Question format
60-70% of H2 headings are questions
H2 count
6-8 H2 sections for a standard blog post
Heading length
Each heading under 70 characters
Step 5: Internal Links
Check
Pass Criteria
Link count
3-10 internal links per post
Anchor text
Descriptive (not "click here" or "read more")
Bidirectional
Check if linked pages also link back (flag if not)
No orphan status
Post links to at least 3 other pages on the site
Link distribution
Links spread across the post, not clustered
No self-links
Post does not link to itself
Use Grep and Glob to scan the project for existing blog content and verify bidirectional linking where possible.
Step 6: External Links
Check
Pass Criteria
Source tier
Links to tier 1-3 sources only (authoritative, not SEO blogs)
Broken links
Use WebFetch to verify top external links are reachable
Rel attributes
External links have appropriate rel attributes (nofollow for sponsored/UGC)
Link count
At least 3 external links to authoritative sources
No competitor links
Not linking to direct competitors unnecessarily
Step 7: Canonical URL
Check
Pass Criteria
Present
Canonical URL is defined in frontmatter or meta tags
Correct format
Full absolute URL (https://domain.com/path )
Trailing slash
Consistent with site convention (no mixed trailing slashes)
Self-referencing
Canonical points to the page itself (unless intentional cross-domain)
Step 8: OG Meta Tags
Check
Pass Criteria
og:title
Present, matches or complements the title tag
og:description
Present, 150-160 characters, compelling for social sharing
og:image
Present, 1200x630 minimum dimensions, absolute URL
og:type
Set to "article" for blog posts
og:url
Present, matches canonical URL
og:site_name
Present, matches site/brand name
Step 9: Twitter Card
Check
Pass Criteria
twitter:card
Set to "summarylarge image" for blog posts
twitter:title
Present, under 70 characters
twitter:description
Present, under 200 characters
twitter:image
Present, same as or similar to og:image
twitter:site
Present if the site has a Twitter/X account
Step 10: URL Structure
Check
Pass Criteria
Length
Short — under 75 characters for the path portion
Keyword presence
Primary keyword or close variant in the URL slug
No dates
URL does not contain /2025/ or /2026/ date segments
No special characters
Only lowercase letters, numbers, and hyphens
Lowercase
Entire URL path is lowercase
No stop words
Minimal use of "the", "a", "and", "of" in slug
No file extension
No .html or .php in the URL (clean URLs)
Step 11: Generate Report
Output a comprehensive SEO validation report in this format:
## SEO Validation Report: [Title]
**File**: [path or URL]
**Date**: [check date]
**Overall**: [X/Y checks passed] — [PASS/NEEDS WORK/FAIL]
### Results
| # | Check | Status | Details | Fix |
|---|-------|--------|---------|-----|
| 1 | Title length | PASS | 52 chars | — |
| 2 | Title keyword | PASS | "keyword" in first half | — |
| 3 | Title power word | FAIL | No power word found | Add "Guide", "Essential", or "Complete" |
| 4 | Meta description length | PASS | 155 chars | — |
| 5 | Meta description stat | FAIL | No number found | Add a key statistic from the post |
| ... | ... | ... | ... | ... |
### Summary
**Passed**: [N] checks
**Failed**: [N] checks
### Priority Fixes
1. [Most impactful fix — what to change and where]
2. [Second most impactful fix]
3. [Third most impactful fix]
### Notes
- [Any observations about overall SEO health]
- [Suggestions for improvement beyond the checklist]
Status values:
PASS — Meets the criteria
FAIL — Does not meet the criteria, fix provided
WARN — Partially meets criteria or edge case, recommendation provided
N/A — Not applicable (e.g., no Twitter Card tags if site has no X account)