seo-crawlability (M1)

Crawl access is the precondition for every other search signal: if Googlebot/Bingbot can't fetch the page and its assets, nothing else ranks. This module covers general-purpose crawl access only. AI-specific bot directives (GPTBot, Claude-SearchBot, etc.) and llms.txt live in seo-ai-crawlers (M14/M21); see references/ai-crawlers.md for that boundary.

Audits

Working from the PageSnapshot (rendered_dom if present, else raw_html) plus a fetch of /robots.txt:

1. Reachability: /robots.txt returns 200 (a 404 means "allow all" but is worth flagging; a 5xx can suspend crawling).
2. Syntax: each line is a valid directive (User-agent, Disallow, Allow, Sitemap, Crawl-delay); flag unknown tokens, missing User-agent group headers, and BOM/encoding issues.
3. Asset blocking: any Disallow that blocks CSS/JS, fonts, or /wp-includes/-style paths — this breaks rendering and is a leading cause of "page looks broken to Google" (cross-check with M-render).
4. Content blocking: Disallow rules that hide important indexable paths from Googlebot/Bingbot.
5. Crawl-delay sanity: a large Crawl-delay (or one applied to the global group) can starve crawl budget; note that Googlebot ignores Crawl-delay but Bingbot honors it.
6. Sitemap directive: presence of at least one absolute Sitemap: URL.
7. Overall access: resolve the effective ruleset for Googlebot and Bingbot against the audited URL — does it end up allowed?

Fixes

Generated edits are a diff for fix, mapped to the schema fixable field:

• AUTO: remove an accidental Disallow of CSS/JS or a key content path (additive un-block, verifiable); add a missing absolute Sitemap: line; repair malformed syntax (e.g. Dissallow typo, missing colon, group with no User-agent header).
• PROPOSED: tightening Crawl-delay or restructuring User-agent groups — drafted, requires per-item accept because intent may be deliberate.
• ADVISORY: changing what is intentionally disallowed (private/staging paths) — never written by the tool.

Never fabricate a sitemap URL or path: if the canonical sitemap location is unknown, emit a clearly-marked TODO placeholder for the user to fill, or ask.

Verification

• node ${CLAUDE_SKILL_DIR}/../../scripts/parse-robots-sitemap.mjs --url <u> — fetches and parses /robots.txt, resolves the effective allow/deny for the named agent + URL, and checks for the Sitemap: directive (method robots_parse).
• When /robots.txt cannot be fetched (network/auth/edge block) the status is needs_api, never a false pass.

Findings

Emit findings per schema/finding.schema.json. Examples:

• M1.robots.blocks_css_js — a Disallow matches CSS/JS the rendered page loads (severity 5, fail, fixable: auto, axis search, confidence established).
• M1.robots.blocks_googlebot — effective ruleset disallows the audited URL for Googlebot (severity 5, fail, fixable: proposed, axis search, confidence established).
• M1.sitemap.missing_directive — no Sitemap: line in robots.txt (severity 5, warn, fixable: auto, axis search, confidence directional).

Each finding: evidence.observed quotes the offending robots.txt line (or the resolved verdict) verbatim; verification.reproduce is the runnable command above; expected_impact is banded + confidence-tagged (no naked %).

Honesty

• robots.txt controls crawling, not indexing: a Disallow-ed page can still be indexed (URL-only) from external links. To keep a page out of the index use a noindex meta tag and do not also Disallow it, or the crawler can't see the noindex.
• A missing or 404 robots.txt is not a defect — it means "crawl everything." Don't report it as a fail; flag only as informational.
• Crawl-delay is ignored by Googlebot; recommending it as a Google ranking/crawl lever is a myth — scope advice to Bingbot and other honoring agents.