Gemini Optimization Checklist: What Google Documents and What Is Hygiene

"Gemini" covers several Google products, and they are governed by different controls. Mixing them up is the most common audit error.

• The Gemini app (Gemini Apps). Google-Extended controls whether your content is used for its training and grounding.
• Google AI Overviews and AI Mode. These live inside Google Search. Googlebot and Search eligibility govern them.
• The Gemini API with Grounding with Google Search. Developers call this separately. Google's API docs say the model automatically generates one or more search queries and runs them.

Google says AI Overviews and AI Mode "may use different models and techniques" and can return different links. The models behind the Gemini app also change often, so treat any model name you read as a snapshot as of October 2026.

If AI Overviews and AI Mode matter more to you than the app, pair this page with the Google AI Mode visibility checklist.

Google-Extended is a robots.txt token, not a separate crawler visit. Google's common crawlers page says it cuts training and grounding use for Gemini Apps and Vertex AI. The same page says it "does not impact a site's inclusion in Google Search nor is it used as a ranking signal."

That gives you a clean, two-way choice:

User-agent: Google-Extended
Disallow: /

This blocks Gemini Apps training and grounding use. Removing that rule, or allowing the path, permits it. Blocking Google-Extended does not remove you from AI Overviews or AI Mode, because those run on Googlebot.

The common failure is accidental. A blanket "block all AI bots" template adds Google-Extended alongside training bots, and nobody records why. Write down the decision, the date and the owner. Then check that your robots.txt matches it. Our AI crawler access audit playbook walks through every token, and the free robots.txt checker for AI crawlers shows what each rule resolves to.

What Google does not document: whether allowing Google-Extended makes Gemini more likely to mention you. Allowing it removes a block. It does not add a lever.

Googlebot is the control for every Google Search surface. Google states that because AI is built into Search, robots.txt directives for Googlebot are the control. There is no robots.txt token that blocks AI Overviews or AI Mode on its own.

Check three things:

1. robots.txt allows Googlebot on the pages that state your products, prices and positioning.
2. Your firewall or CDN lets Googlebot through. Bot-management rules can turn away crawlers that robots.txt allows. How often this happens is not measured, so treat it as hygiene and test it rather than assume it.
3. Your content renders. Googlebot renders JavaScript, unlike most other AI crawlers tested. Server-side rendering matters less for Google than for ChatGPT or Claude, but it still protects you everywhere else. See the Claude visibility checklist for that side.

Google also documents a per-URL fetch limit of 2MB of HTML for Googlebot. Google says the vast majority of sites never hit it, so only act if a page exceeds it.

For AI Overviews and AI Mode, this step is documented. Google's AI features page says a page "must be indexed and eligible to be shown in Google Search with a snippet" to be a supporting link, with "no additional technical requirements." It adds that indexing and serving "isn't guaranteed."

For the Gemini app, Google does not document the link to its Search index in the sources we hold. Treat index health as hygiene there. One public test points the same way: in Otterly's 2,000 AI blogs experiment, Google deindexed both test sites, and Gemini, AI Overviews and AI Mode almost never cited them. That is one pair of sites, so read it as an association, not proof.

What to verify:

• Index status of your key URLs in Google Search Console. A crawl cannot tell you this.
• Snippet controls. Search your templates for noindex, nosnippet, max-snippet:0 and data-nosnippet. Google documents these as the controls that keep content out of AI features. They are often inherited from a template by accident.
• The Search Console generative AI control. Inclusion is on by default, but the control is opt-out, it can inherit from a parent property, and it is invisible from outside. As of October 2026 it covers AI Overviews, AI Mode and Discover generative AI features.

Gemini can only repeat what it finds or already knows. If your pricing page, about page and footer state different numbers, you've given the engine three answers to choose from.

The evidence supports one narrow positive point: stating a specific fact (a price, a number, a one-line definition) on a fetchable page gives an engine a sentence it can quote. It does not promise that Gemini will quote it.

• List the 10 to 20 facts a buyer would ask about: plans and prices, founding year, location, product names, integrations.
• Find every place each fact appears on your site and make them match.
• Put each one in plain HTML text, not only in an image or a script-loaded widget.
• Fix the outdated ones on third-party pages you can edit, such as directory listings.

This is hygiene, not a documented control. It's on the list because it addresses the complaint brands actually have: an AI answer that gets a specific fact wrong.

You cannot see the queries Gemini actually runs. Google's API docs say grounding generates its own search queries, and nobody outside Google observes them. So any prompt test is a proxy. Run it consistently anyway.

1. Write 5 to 10 questions a buyer would ask, in their words.
2. Run each one where grounding is visible, so you can see whether sources appear. An answer with no citations may come from what the model already knows rather than a live search.
3. Record the date, the surface (Gemini app, AI Overviews or AI Mode), the answer, the cited URLs, and any wrong facts.
4. Repeat on a fixed schedule and compare. A quarterly AI visibility review is a workable rhythm.

Keep Gemini's results separate from other engines. A blended score hides which surface is failing. For a quick first look, the free Gemini brand check explains what a single run can and cannot tell you.

Several items appear on most Gemini checklists and are missing here on purpose.

• Schema markup. Google says structured data isn't required for generative AI search. Ahrefs' matched test of 1,885 pages found no major uplift, and AI Overviews citations fell 4.6%. Existing markup does no harm, but it isn't a lever.
• llms.txt. Google's optimization guide says Google Search ignores it.
• "AI-friendly" writing and chunking. Google's guide says you don't need to write in a specific way for generative AI search, and that there's no ideal page length.
• E-E-A-T scores. Google says E-E-A-T isn't a specific ranking factor. No score exists to improve.

The reason is simple. The steps with real support remove blocks. They don't add an advantage. For the wider order of work across engines, see GEO optimization: a practical order of work.