AEO Cannibalization Detector

Source: github.com/psyduckler/aeo-skills Part of: AEO Skills Suite

Detect when your own pages compete against each other for the same slots in Gemini's candidate set.

Background

Influence over AI answers happens at retrieval, not inside the model. When Gemini searches the web to answer a prompt, it builds a candidate set of pages to cite. If two of your own pages both enter that candidate set for the same prompt, you're competing against yourself — Gemini alternates between citing page A and page B, diluting the citation strength of both.

This matters because influence compounds through repeated inclusion in the recurring retrieval set. A page that gets cited 90% of the time is building authority. Two pages that each get cited 40% are neither building authority. In a search-first system like Gemini, where every response triggers web retrieval, having a single strong page in the candidate set beats splitting your authority across competing pages.

Defaults

• Model: gemini-3-flash-preview — the same model powering Google AI Overviews
• Samples: 20 runs per prompt — enough to detect citation splits

Requirements

• Gemini API key (free from aistudio.google.com) — set as GEMINI_API_KEY env var
• Python 3.9+
• No pip dependencies (stdlib only)

Usage

# Check two prompts for cannibalization
GEMINI_API_KEY="$GEMINI_API_KEY" python3 scripts/detect.py --domain acme.com \
    "best content optimization tools" \
    "SEO content software"

# Load prompts from a file
GEMINI_API_KEY="$GEMINI_API_KEY" python3 scripts/detect.py --domain acme.com --prompts-file prompts.txt

# Both positional prompts and file, JSON output
GEMINI_API_KEY="$GEMINI_API_KEY" python3 scripts/detect.py --domain acme.com \
    "content optimization" \
    --prompts-file more-prompts.txt \
    --output json

# Higher confidence with more runs
GEMINI_API_KEY="$GEMINI_API_KEY" python3 scripts/detect.py --domain acme.com \
    "best SEO tools" --runs 30

Run from the skill directory. Resolve scripts/detect.py relative to this SKILL.md.

Options

Output

Text Output

Cannibalization Detector: acme.com
Model: gemini-3-flash-preview | Runs per prompt: 20

RESULTS BY PROMPT:
======================================================================

"best content optimization tools"
  Runs: 20 | Domain URLs found: 3
  Status: 🔴 HIGH cannibalization
  Competing URLs:
    45% (9/20) /blog/content-optimization-tools — Best Content Optimization Tools (2025)
      https://acme.com/blog/content-optimization-tools
    35% (7/20) /product — Acme - Content Optimization Platform
      https://acme.com/product
    15% (3/20) /blog/seo-content-tools — SEO Content Tools Guide
      https://acme.com/blog/seo-content-tools
  → No single URL exceeds 50% citation rate. Gemini can't decide which
    of your pages to cite — citations are diluted across 3 URLs.
    Strongly recommend consolidating into one comprehensive page.

"SEO content software"
  Runs: 20 | Domain URLs found: 1
  Status: ✓ No cannibalization
    85% — https://acme.com/product
  No cannibalization — single URL cited consistently.

SUMMARY:
======================================================================
  Domain: acme.com
  Prompts analyzed: 2
  Cannibalization detected: 1/2
  Severity: HIGH: 1

  Worst offenders:
    🔴 "best content optimization tools" — HIGH (3 URLs, max 45%)

JSON Output

Structured JSON with per-prompt cannibalization details (severity, URLs, rates) and a summary with worst offenders.

Severity Levels

How It Works

1. Runs each prompt 20 times against Gemini with Google Search grounding
2. Extracts all cited URLs from grounding chunks
3. Filters to URLs matching the target domain
4. If 2+ different domain URLs appear across runs for the same prompt → cannibalization detected
5. Scores severity based on the top URL's citation rate
6. Recommends consolidation (merge pages) or differentiation (make topics distinct)

Tips

• Run this before creating new content — check if an existing page already targets the same prompt
• HIGH severity is your highest priority: consolidate those pages into one comprehensive resource
• MEDIUM severity might mean the pages cover overlapping subtopics — consider differentiating with clearer focus
• LOW severity is usually fine — the right page is winning, the other just appears occasionally
• Pair with aeo-source-authority-profiler to understand what the winning competing page does differently
• Pair with aeo-multi-prompt-strategy to see if competing pages are winning different prompts (deliberate vs accidental)
• Use --prompts-file with a list of your target prompts for a full site audit

References

Notes

• Gemini API key stored in macOS Keychain under google-api-key
• Prompts file supports comments (lines starting with #) and blank lines
• Retries API calls up to 5 times with exponential backoff
• Subdomains are matched — blog.example.com counts as example.com