blog-seo-check

# 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 5.5: Link Deduplication

| Check | Pass Criteria |
|-------|---------------|
| No duplicate URLs | Each URL appears at most once in body content |
| Best instance kept | If duplicates exist, keep the one with most descriptive anchor text |
| Navigation exempt | Header/footer nav links don't count toward body dedup |
| Fragment normalization | URLs with different #fragments treated as same URL |

For each duplicate found:
1. Normalize URLs (strip trailing slashes, query parameters, fragments)
2. Score each instance by anchor text descriptiveness (keyword-rich > generic)
3. Recommend keeping the highest-scored instance, removing others
4. Deduct 1 point per duplicate from SEO Optimization score

Google records 1-2 anchor texts per URL per page (Zyppy 2023). Optimal: link to
same URL once in body content; 5-10 internal links per 2,000 words; max ~50 total
links per page.

### 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 |

### FLOW evidence triple (citations)

For every public statistic in the post, verify all three components:

- Year anchor appears in prose ("In 2026," or "As of Q1 2026,") BEFORE the statistic, not buried in parentheses.
- Inline citation names the publisher AND the document title (or report name).
- Source block at the bottom of the post includes the URL plus `retrieved YYYY-MM-DD` for each cited source.

Posts that fail any of the three either drop the unverifiable claim or replace it with a verified alternative. See `skills/blog/references/flow-alignment.md`. For a one-shot prompt-driven check, see `/blog flow optimize`.

### 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 "summary_large_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 |
|-------|----------