What llms.txt is
A proposed convention: a plain-text file at the root of a site that lists its key pages for large language models. It is not an official standard adopted by Google.
Where the time is better spent
On practice pages that answer client questions directly, on crawler settings that let search crawlers in, and on structured data that matches each page. See which AI crawlers to allow and whether schema helps.
Go deeper
The AI SEO guide covers the technical foundation in full.