What is llms.txt and should my business website have one?

llms.txt is a plain-text Markdown file placed at your website's root (yoursite.com/llms.txt) that summarizes who you are and links to your most important pages, written for large language models and AI assistants. It typically includes a one-paragraph description, key facts like location, services, contact and pricing approach, and links to main pages with short descriptions. It's a proposed standard: not every AI tool reads it yet, and it won't replace good pages, schema and consistent listings. But it takes under an hour to create and costs nothing. McCrawAI builds these as part of AI visibility work, alongside the schema and consistent listings that matter more.