Form fields an AI agent can't fill in

An AI agent filling in a form for someone (a booking, a sign-up, a search) finds the fields in the page's accessibility tree and learns what each one wants from its label. Google says browser agents work partly by "interpreting the accessibility tree", and Chrome's checks for agents say "missing labels can block users with visual disabilities and agents from completing a task". A field with only a placeholder has no label there, so the agent is left guessing which box is the email and which the phone number.

The accessibility pack has the same check for the people who use screen readers; with both packs on you hear it once.

Sources: Google's guide to generative AI features in Search, Chrome: accessibility for agents, Chrome: agentic browsing scoring.

Give every field a label:

<label for="email">Email address</label>
<input id="email" type="email" name="email">

Where the design has no room for visible words, name the field with aria-label.