Seo Meta Onpage

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).

Audits

Working from the PageSnapshot (rendered_dom if present, else raw_html):

1. Title — exactly one ``; length 50-60 chars (warn outside the band, fail if missing or empty, fail if duplicated site-wide across distinct URLs). Not all caps; not pure keyword list.
2. Meta description — present, 150-160 chars (warn outside, not fail — Google may rewrite it); not duplicated site-wide; describes the page, not boilerplate.
3. Viewport — `` present (fail if missing — mobile rendering/indexing depends on it).
4. Charset — ` present and in the first 1024 bytes of `.
5. Language — `` present and a valid BCP-47 tag.
6. Robots meta — sanity-check `: 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 `, do not adjudicate it.

Fixes

• AUTO — add missing viewport, charset (utf-8), and ` (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 ` and meta description from `, 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_SKILL_DIR}/../../scripts/parse-html.mjs --url (or --file ) — 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. Examples:

• M7.title.missing — no ` (fail, severity 3, fixable: proposed, axis search, confidence established`).
• M7.title.length_out_of_band — title 78 chars, truncates in SERP (warn, severity 3, fixable: proposed, axis search, confidence directional).
• M7.viewport.missing — no responsive viewport (fail, severity 3, fixable: auto, axis search, confidence established).

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 (pixel-width truncation), not ranking factors — over-band values are warn, not fail, and impact is directional at most.
• 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.

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: Hainrixz
• Source: Hainrixz/claude-seo-ai
• License: MIT
• Homepage: https://tododeia.com

Install and usage instructions live in the source repository linked above.