seo-meta-onpage (M7)
Head hygiene is cheap, deterministic, and the first thing every crawler reads. Reference: references/schema-tier1.md for the structured-data layer that sits alongside the head (owned by M5).
Inputs
Work from the PageSnapshot named in your dispatch envelope: read parsed from <run_dir>/pages/<slug>.json (title, metas[], robots_meta[], canonicals[], word_count) plus headers (content-language, x-robots-tag); Grep pages/<slug>.html for verbatim evidence; site artifacts live in <run_dir>/site/{robots.json,sitemaps.json,discovery.json}. Deterministic findings already emitted by audit.mjs are listed in <run_dir>/findings.deterministic.json — do not re-emit those ids; add model-judged findings only. If invoked directly with a URL/path and no snapshot exists, first run node "${CLAUDE_PLUGIN_ROOT}/scripts/snapshot.mjs" <target> --out "${CLAUDE_PLUGIN_DATA}/runs" and use the printed snapshot path.
Audits
Working from the PageSnapshot (parsed_rendered when render.used is not none, else parsed):
- Title — exactly one
<title>. Length is judged against the shared bands in scripts/lib/bands.mjs (the single source; parse-html.mjs, the on-page checks and this skill all read it): pass 30-60 characters, recommended 50-60. Inside 50-60 the verdict is recommended; inside 30-60 but outside that, pass; below 30 short, above 60 long — both are warn, never fail. Fail only when the title is missing or empty, or duplicated site-wide across distinct URLs. Not all caps; not a pure keyword list.
- Meta description — present, judged against the same shared bands: pass 70-160 characters, recommended 150-160. Outside the pass band is
warn, never fail — Google rewrites descriptions freely. Not duplicated site-wide; describes this page, not boilerplate.
- Viewport —
<meta name="viewport" content="width=device-width, initial-scale=1"> present (fail if missing — mobile rendering/indexing depends on it).
- Charset —
<meta charset="utf-8"> present and in the first 1024 bytes of <head>.
- Language —
<html lang="…"> present and a valid BCP-47 tag.
- Robots meta — sanity-check
<meta name="robots">: flag an accidental noindex/nofollow on a page meant to rank. Full indexability/canonical logic (including the canonical tag) is owned by seo-indexability (M2) — here only note presence of <link rel="canonical">, do not adjudicate it.
Fixes
- AUTO — add missing
viewport, charset (utf-8), and <html lang> (inferred from Content-Language header or page text; leave a TODO if ambiguous). These are deterministic, additive, verifiable writes → diff for fix.
- PROPOSED — generate/trim a
<title> and meta description from <h1>, lead paragraph, and primary topic: length-bounded, keyword-aware but not stuffed, brand suffix only if the site uses one. Each is a draft requiring per-item accept (humans own messaging).
- ADVISORY — removing an intentional
noindex is never auto-written; surface it and let the user decide.
- Never fabricate a title, description, or
lang — when content is too thin to derive a value, leave a clearly-marked TODO: placeholder for the user to fill.
Verification
- Method
dom_assert: node "${CLAUDE_PLUGIN_ROOT}/scripts/parse-html.mjs" --snapshot <pages/<slug>.json> (or --url <u> / --file <path>) — returns title (value/length/ok), meta_description (value/length/ok), robots_meta, canonical, and head_hygiene (viewport/charset/lang) so each head element's presence and length is asserted directly against the snapshot.
- Duplicate-title/description checks need the full crawl set; when only a single page is available the cross-URL assertion is reported
needs_api, never a false pass.
Findings
Findings conform to schema/finding.schema.json. Severity policy: 5 is reserved for catastrophic, eligibility-killing facts at site/template scope; 4 major · 3 moderate · 2 minor · 1 cosmetic · 0 informational — and only an established severity-5 fail in an active category can cap a score (references/scoring-model.md). Head hygiene never reaches 5. Examples:
M7.title.missing — no <title> (fail, severity 3, fixable: proposed, axis search, confidence established).M7.title.length_out_of_band — title 78 chars, outside the 30-60 pass band and likely truncated in the SERP (warn, severity 3, fixable: proposed, axis search, confidence directional). Quote the length and the band that produced the verdict.M7.description.length_out_of_band — description outside the 70-160 pass band (warn, severity 2, fixable: proposed, axis search, confidence directional).M7.viewport.missing — no responsive viewport (fail, severity 3, fixable: auto, axis search, confidence established).M7.title.duplicate_across_urls — the same <title> is served from several sampled URLs (warn, severity 3, fixable: proposed, axis search, confidence directional). One finding per duplicate cluster, quoting the shared title and the URLs.M7.description.duplicate_across_urls — the same meta description is served from several sampled URLs (warn, severity 2, fixable: proposed, axis search, confidence directional).
Both duplicate checks are cross-URL: with fewer than two content pages in the run they are reported once as M7.title.duplicate_across_urls with status needs_api (severity 0, unscored), never as a pass.
Platform-conditional ids. This module also emits 6 ids that fire only when profile.json names the platform (shopify, wordpress, nextjs, gatsby, jekyll, react-router). They are indexed in references/routing.md § Platform-conditional finding ids and specified in references/platforms/<id>.md §10.
Each finding: evidence.observed quotes the head verbatim (e.g. the exact title string + its length); verification.reproduce is the runnable parse-html.mjs command above; expected_impact is banded + confidence-tagged (no naked %).
Honesty
- The "meta keywords" tag is dead — Google ignores it; do not add or recommend it.
- Title/description length bands are SERP-display heuristics (Google truncates on pixel width, not characters), not ranking factors — out-of-band values are
warn, never fail, and impact is directional at most. The pass band is deliberately wider than the recommended band so a 35-character title is not reported as a defect; both bands come from scripts/lib/bands.mjs so the script, the report, and this skill can never disagree.
- Google frequently rewrites the displayed title/description from on-page content; a perfect tag is not guaranteed to appear, so never promise a SERP snippet as a ranking gain.
1---2name: seo-meta-onpage3description: Audit and generate the document head — title and meta description length against the shared bands (title pass 30-60 chars, recommended 50-60; description pass 70-160, recommended 150-160), viewport, charset, <html lang>, and robots-meta sanity — flagging missing/duplicate/out-of-band values and producing length-bounded, keyword-aware replacements. Module M7. Feeds the Search SEO score.4---56# seo-meta-onpage (M7)78Head hygiene is cheap, deterministic, and the first thing every crawler reads. Reference: `references/schema-tier1.md` for the structured-data layer that sits alongside the head (owned by M5).910## Inputs11Work from the PageSnapshot named in your dispatch envelope: read `parsed` from `<run_dir>/pages/<slug>.json` (`title`, `metas[]`, `robots_meta[]`, `canonicals[]`, `word_count`) plus `headers` (`content-language`, `x-robots-tag`); Grep `pages/<slug>.html` for verbatim evidence; site artifacts live in `<run_dir>/site/{robots.json,sitemaps.json,discovery.json}`. Deterministic findings already emitted by `audit.mjs` are listed in `<run_dir>/findings.deterministic.json` — do not re-emit those ids; add model-judged findings only. If invoked directly with a URL/path and no snapshot exists, first run `node "${CLAUDE_PLUGIN_ROOT}/scripts/snapshot.mjs" <target> --out "${CLAUDE_PLUGIN_DATA}/runs"` and use the printed snapshot path.1213## Audits14Working from the PageSnapshot (`parsed_rendered` when `render.used` is not `none`, else `parsed`):151. **Title** — exactly one `<title>`. Length is judged against the **shared bands** in `scripts/lib/bands.mjs` (the single source; `parse-html.mjs`, the on-page checks and this skill all read it): **pass 30-60 characters**, **recommended 50-60**. Inside 50-60 the verdict is `recommended`; inside 30-60 but outside that, `pass`; below 30 `short`, above 60 `long` — both are `warn`, never `fail`. **Fail** only when the title is missing or empty, or duplicated site-wide across distinct URLs. Not all caps; not a pure keyword list.162. **Meta description** — present, judged against the same shared bands: **pass 70-160 characters**, **recommended 150-160**. Outside the pass band is `warn`, never `fail` — Google rewrites descriptions freely. Not duplicated site-wide; describes this page, not boilerplate.173. **Viewport** — `<meta name="viewport" content="width=device-width, initial-scale=1">` present (fail if missing — mobile rendering/indexing depends on it).184. **Charset** — `<meta charset="utf-8">` present and in the first 1024 bytes of `<head>`.195. **Language** — `<html lang="…">` present and a valid BCP-47 tag.206. **Robots meta** — sanity-check `<meta name="robots">`: flag an accidental `noindex`/`nofollow` on a page meant to rank. Full indexability/canonical logic (including the canonical tag) is owned by **seo-indexability (M2)** — here only **note presence** of `<link rel="canonical">`, do not adjudicate it.2122## Fixes23- **AUTO** — add missing `viewport`, `charset` (utf-8), and `<html lang>` (inferred from `Content-Language` header or page text; leave a TODO if ambiguous). These are deterministic, additive, verifiable writes → diff for `fix`.24- **PROPOSED** — generate/trim a `<title>` and `meta description` from `<h1>`, lead paragraph, and primary topic: length-bounded, keyword-aware but **not** stuffed, brand suffix only if the site uses one. Each is a draft requiring per-item accept (humans own messaging).25- **ADVISORY** — removing an intentional `noindex` is never auto-written; surface it and let the user decide.26- **Never fabricate** a title, description, or `lang` — when content is too thin to derive a value, leave a clearly-marked `TODO:` placeholder for the user to fill.2728## Verification29- Method `dom_assert`: `node "${CLAUDE_PLUGIN_ROOT}/scripts/parse-html.mjs" --snapshot <pages/<slug>.json>` (or `--url <u>` / `--file <path>`) — returns `title` (value/length/ok), `meta_description` (value/length/ok), `robots_meta`, `canonical`, and `head_hygiene` (viewport/charset/lang) so each head element's presence and length is asserted directly against the snapshot.30- Duplicate-title/description checks need the full crawl set; when only a single page is available the cross-URL assertion is reported `needs_api`, **never** a false `pass`.3132## Findings33Findings conform to `schema/finding.schema.json`. **Severity policy**: 5 is reserved for catastrophic, eligibility-killing facts at site/template scope; 4 major · 3 moderate · 2 minor · 1 cosmetic · 0 informational — and only an `established` severity-5 `fail` in an active category can cap a score (`references/scoring-model.md`). Head hygiene never reaches 5. Examples:34- `M7.title.missing` — no `<title>` (fail, severity 3, `fixable: proposed`, axis `search`, confidence `established`).35- `M7.title.length_out_of_band` — title 78 chars, outside the 30-60 pass band and likely truncated in the SERP (warn, severity 3, `fixable: proposed`, axis `search`, confidence `directional`). Quote the length and the band that produced the verdict.36- `M7.description.length_out_of_band` — description outside the 70-160 pass band (warn, severity 2, `fixable: proposed`, axis `search`, confidence `directional`).37- `M7.viewport.missing` — no responsive viewport (fail, severity 3, `fixable: auto`, axis `search`, confidence `established`).38- `M7.title.duplicate_across_urls` — the same `<title>` is served from several sampled URLs (warn, severity 3, `fixable: proposed`, axis `search`, confidence `directional`). One finding per duplicate cluster, quoting the shared title and the URLs.39- `M7.description.duplicate_across_urls` — the same meta description is served from several sampled URLs (warn, severity 2, `fixable: proposed`, axis `search`, confidence `directional`).40Both duplicate checks are cross-URL: with fewer than two content pages in the run they are reported once as `M7.title.duplicate_across_urls` with status `needs_api` (severity 0, unscored), never as a pass.41**Platform-conditional ids.** This module also emits 6 ids that fire only when `profile.json` names the platform (`shopify`, `wordpress`, `nextjs`, `gatsby`, `jekyll`, `react-router`). They are indexed in `references/routing.md` § Platform-conditional finding ids and specified in `references/platforms/<id>.md` §10.4243Each finding: `evidence.observed` quotes the head verbatim (e.g. the exact title string + its length); `verification.reproduce` is the runnable `parse-html.mjs` command above; `expected_impact` is banded + confidence-tagged (no naked %).4445## Honesty46- The "meta keywords" tag is dead — Google ignores it; do not add or recommend it.47- Title/description length bands are SERP-display heuristics (Google truncates on pixel width, not characters), not ranking factors — out-of-band values are `warn`, never `fail`, and impact is `directional` at most. The **pass** band is deliberately wider than the **recommended** band so a 35-character title is not reported as a defect; both bands come from `scripts/lib/bands.mjs` so the script, the report, and this skill can never disagree.48- Google frequently **rewrites** the displayed title/description from on-page content; a perfect tag is not guaranteed to appear, so never promise a SERP snippet as a ranking gain.
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