A checklist to pass the Agentic Browsing audit

The Lighthouse and PageSpeed Insights guides explain what the Agentic Browsing checks are and why they exist. This is the other page: the ordered, do-this-then-that checklist for actually passing them. The trick is sequence. Two of the checks are real UX work that pays off for humans regardless, one is a fifteen-minute freebie, and one is optional and most sites should skip it. Work them in order of payoff and you clear the audit without wasting effort on the part that helps no one.

00 · BaselineStep 0: run it and read the ratio

Before fixing anything, measure. Two ways to run it:

npm install -g lighthouse@latest
lighthouse https://yoursite.com --view

Or open pagespeed.web.dev, enter your URL, and read the Agentic Browsing section. Remember the denominator: PageSpeed Insights runs three checks (so you are aiming for 3/3), while the Lighthouse CLI on Chrome 150+ with the WebMCP origin trial shows a fourth. Note which specific checks are red; that is your to-do list, and the rest of this page is in the order you should tackle them.

01 · Highest payoffStep 1: fix the accessibility tree

Do this first, because it is the check that most often fails and the one that most helps everyone else. Agents locate and operate controls through the accessibility tree, the same structured model a screen reader uses, so an unnamed control is invisible to them.

The core fixes:

• Use real semantic elements: <button>, <a>, <nav>, <main>, real headings, not <div> with a click handler.
• Give every interactive element an accessible name: visible text, an associated <label> for inputs, or an aria-label on icon-only buttons.
• Do not bury real content behind aria-hidden, and keep the heading order sane.

If your Lighthouse Accessibility score is already strong, you likely pass this for free. The full reasoning and a deeper fix list are in your accessibility tree is now your agent API.

02 · Stop the jumpStep 2: fix layout stability

Next, stop your page moving after it loads. An agent computes where a control is and clicks there; if your layout shifts in between, it clicks the wrong thing. This is the same Cumulative Layout Shift metric from the Performance category, judged for machines.

The standard fixes:

• Set explicit width and height (or aspect-ratio) on images, video, and iframes.
• Reserve space for anything that loads late: ads, embeds, banners, cookie notices.
• Preload web fonts and use font-display sensibly so text does not reflow on swap.
• Never inject content above content that is already on screen.

Aim for CLS under 0.1. The agent-specific reasoning and the full fix set are in why layout shift breaks AI agents.

03 · The fifteen-minute winStep 3: ship a valid llms.txt

Now clear the cheap one. The audit wants a file at your root with an H1, at least one Markdown-formatted link, and more than 50 characters. The smallest file that passes:

# Acme

> Acme turns messy invoices into clean spreadsheets in one click.

## Docs

- [Getting started](https://acme.com/docs/start)
- [Pricing](https://acme.com/pricing)

Use real Markdown links, not bare URLs, or the check fails. Whether llms.txt does anything beyond passing this audit is a separate, honest question covered in do AI crawlers actually read llms.txt; for the checklist, present and well-formed is all you need.

04 · Only if agents are your channelStep 4 (optional): add WebMCP tools

This is the step most sites should skip. WebMCP lets you hand agents explicit tools instead of making them guess, but it needs the origin trial, does nothing for human visitors, and does not even run in PageSpeed Insights. Only reach for it if AI agents are a genuine channel for your product (commerce, an API, a tool). If they are, start with the declarative path: annotate your one or two most important forms (search, add-to-cart, book) and leave the rest.

05 · Re-run and stopWhat "done" looks like

Re-run the audit. In PageSpeed Insights, 3/3 is a full pass and the right place to stop for most sites. Do not chase a single flaky reading: if the ratio wobbles while your code has not changed, it is a borderline layout shift, so widen your reserved space rather than re-running twenty times. And keep the whole thing in proportion. Passing this audit means an agent can use your site; it does not mean an agent will visit, which is the Footprint problem no audit measures.