cornerstone-content-audit

name	Cornerstone-Content-Audit
type	playbook
description	Use when running a cornerstone content audit, pillar content review, or content architecture audit. End-to-end: discover pages, identify cornerstones, health audit, cannibalization check, and enhancement plan.
version	0.1.0

Cornerstone Content Audit

Also known as: top-down cornerstone audit.

Overview

Audits a site's most important content — the 3–7 cornerstone pages that should rank highest, attract links, and be cited by AI search. Identifies those pages, evaluates health across traditional and AI-era dimensions, detects cannibalization and pruning opportunities, and produces a prioritized enhancement plan.

Hub & Spoke is the content architecture — one hub owns a topic cluster; spokes answer sub-intents and link up. Cornerstone is the quality standard for those pages (depth, intent, linking, fan-out, citability) — not a separate architecture. Use this playbook when cornerstones are already known or nominated from a catalog.

Not this playbook: Messy site, accidental hubs, or GSC/GA4 triangulation before you trust the architecture → Hub & Spoke Discovery & Recovery.

Architecture

Step	Skill	Location
Phase 1	Site Content Catalog	../../skills/site-content-catalog/SKILL.md
Phase 3b	Fan-Out Coverage Analysis	../../skills/fan-out-coverage-analysis/SKILL.md
Phase 3c	Information Gain Evaluator	../../skills/information-gain-evaluator/SKILL.md
Phase 4a	SEO Cannibalization Audit	../../skills/seo-cannibalization-audit/SKILL.md
Phase 5h	robots.txt Audit	../../skills/robots-txt-audit/SKILL.md

Read each linked SKILL.md before calling it. Follow its workflow exactly.

Input policy (non-negotiable)

Collect from the user:

1. Domain or sitemap URL — required
2. Scope — quick scan (Phases 1–2), single-page cornerstone review (Phase 3 for one URL), or full audit (Phases 1–6)
3. Known cornerstones (optional) — skip Phase 2 nomination when provided
4. Optional context — protected pages, topic clusters, architecture notes (never from workspace or examples)

If domain/sitemap is missing, ask once. Do not invent URLs, metrics, or recommendations before tool results exist.

First response rules

On the first user-facing response:

1. Name the scope (quick scan | single-page | full audit).
2. Name exact skills for that scope (see Architecture).
3. Preview deliverable shape for that scope.
4. State the Phase 2 approval checkpoint when nomination is involved.
5. Frame recommendations around audit dimensions (rankings, fan-out, information gain, AI citability, cannibalization, pruning, AI crawler permissions via robots.txt).

Use AskQuestion for Phase 2 approval when available; otherwise wait for explicit user confirmation.

---

Phase 1: Discovery & catalog

Call: Site Content Catalog

Pass sitemap URL or domain. Receive handoff JSON v1.0 (REFERENCE.md in catalog skill). Read limitations[] — v1.0 does not include inbound internal link counts.

If the catalog returns >200 pages, scope down with the user (path prefix, page type, or top traffic).

Output: Validated page catalog ready for cornerstone scoring.

---

Phase 2: Cornerstone identification

Goal: 3–7 cornerstones grouped by topic cluster.

Step 2a: Topic clusters

From the Phase 1 catalog:

• Group by URL path, title themes, keyword clusters
• Target 3–7 distinct topic areas with a clear head topic each

Step 2b: Score candidates

Per cluster, score top 3–5 candidates:

Signal	Source	Weight
Keyword authority	dataforseo_labs_google_ranked_keywords — volume sum for top-20 ranks	High
Estimated traffic value	Same — ETV	High
Backlink authority	backlinks_summary — referring domains	High
Internal link gravity	Catalog — inbound internal links	Medium
Content depth	Catalog — length, headings	Medium
Navigation prominence	Top nav? Clicks from homepage?	Medium
Freshness	Catalog last modified	Low

Step 2c: Nominate

Per cluster, nominate highest scorer. Flag flat scores, wrong-page cornerstones (blog beats LP), or competing pages.

Human checkpoint

Present nominations with URL, score, and rationale. Do not proceed to Phase 3 until the user approves or adjusts.

Output: Confirmed 3–7 cornerstones with topic clusters and primary keywords.

---

Phase 3: Health audit

Run for each confirmed cornerstone (parallel OK).

3a: Traditional SEO scorecard

Dimension	Source
Rankings	dataforseo_labs_google_ranked_keywords
Backlinks	backlinks_summary
Internal links	Phase 1 catalog
Content	on_page_content_parsing or WebFetch
SERP features	serp_organic_live_advanced

3b: Fan-out coverage

Call: Fan-Out Coverage Analysis

Pass: keyword, domain, anchor_url (cornerstone URL).

3c: Information gain

Call: Information Gain Evaluator

Pass: target_url, primary_keyword.

3d: AI citability

1. ai_opt_llm_ment_search — domain in LLM mentions for primary keyword
2. ai_opt_llm_ment_top_pages — pages AI cites for keyword
3. Structure check (WebFetch): H2/H3 hierarchy, data tables, FAQ blocks, extractable passages
4. Crawlability flag (lightweight): if robots.txt is already fetched in-session, note whether this cornerstone path is blocked for Googlebot or major AI answer bots — full policy audit remains Phase 5h

3e: Scorecard template

## Scorecard: {cornerstone URL}
**Topic cluster:** {name}
**Primary keyword:** {kw} | Rank: #{pos} | Volume: {vol}/mo

### Traditional SEO
- Rankings: {top-20 count, ETV}
- Backlinks: {referring domains}
- Internal links: {inbound, outbound}
- Content: {words, headings, last updated}
- SERP features: {snippet, PAA, sitelinks}

### Fan-Out Coverage: {X}% ({covered}/{total})
### Information Gain: {High/Medium/Low}
### AI Citability: {mentions, competing pages, structure}

---

Phase 4: Cannibalization & pruning

4a: Cannibalization check

Call: SEO Cannibalization Audit

Pass cornerstone URLs, primary keywords, domain, and optional protected pages from user context.

4b: Pruning candidates

From Phase 1 catalog, flag pages with:

• Zero ranked keywords
• Near-zero backlinks
• Thin content (<300 words)
• Topical overlap with a cornerstone

Classify: Consolidate | Improve | Deindex | Delete

Output: Cannibalization conflicts + pruning list.

---

Phase 5: Enhancement plan

Synthesize Phases 3–4. Per cornerstone: content (from 3c), internal links (from 3b), keyword realignment, SERP features, fan-out gap content, cannibalization fixes, pruning.

5h: robots.txt and AI crawler policy

Call: robots.txt Audit

Pass:

• domain
• key_pages — confirmed cornerstone URLs from Phase 2
• crawl_policy — default max_discovery unless user specifies otherwise

Receive handoff JSON v1.0 (REFERENCE.md in robots skill) for the report's crawler policy section.

Cross-check when available:

• Phase 1 catalog — sitemap URLs blocked by Disallow
• Phase 3d — weak AI mentions plus blocked answer bots → flag as likely discoverability issue
• Phase 4 pruning — pages marked Deindex vs training-crawler exposure (note only; do not block audit)

Prioritization

• Quick wins: internal links, title/meta/H1, schema, robots.txt fixes that unblock cornerstones or wrongly block discovery crawlers
• Medium effort: freshness, information gain, heading structure, clear pruning
• Strategic: new cluster content, major rewrites, architecture changes

---

Phase 6: Report

# Cornerstone Content Audit — {domain} — {date}

## Executive Summary
## Topic Cluster Map
## Cornerstone Scorecards
## Cannibalization & Pruning
## Enhancement Plan
### Quick Wins / Medium Effort / Strategic Projects
## New Content Opportunities
## robots.txt & AI Crawler Policy
## Appendix: Full Page Catalog

---

Scope options

User says	Phases
Quick scan / identify cornerstones	1–2
Audit {URL}	3 only
Full audit	1–6
Fan-out for {keyword}	Fan-out skill only
Information gain on {URL}	Information gain skill only

---

When to use which playbook

Situation	Playbook
Known cornerstones, health check only	This playbook
Messy site, accidental hubs, new client	Hub & Spoke Discovery & Recovery
Have GSC/GA4 exports, need triage fast	Hub & Spoke Discovery & Recovery Phases 1a–2
Single keyword / fan-out gap	Fan-Out Coverage Analysis only

---

DataForSEO tools used

dataforseo_labs_google_keywords_for_site, dataforseo_labs_google_ranked_keywords, dataforseo_labs_google_relevant_pages, dataforseo_labs_google_related_keywords, dataforseo_labs_google_keyword_suggestions, dataforseo_labs_google_keyword_ideas, backlinks_summary, serp_organic_live_advanced, on_page_content_parsing, ai_opt_llm_ment_search, ai_opt_llm_ment_top_pages

Research basis

Cornerstone content practice (Yoast, HubSpot, etc.) plus 2025–2026 GEO: AI Overview fan-out, information gain for citations, selective robots.txt crawler policy (RFC 9309; training vs answer/search bots), content pruning impact, structured-content citation lift.

Requirements: REQUIREMENTS.md