Why it matters
Agents follow llms.txt links directly; 404s waste their context and tool calls.
How to fix it
Generate llms.txt from the same content source as your routes, and point links at .md mirrors that exist.
References
More ai search rules
void geo reports 41 rules in this category. Generative-engine optimisation: whether AI crawlers that don't run JavaScript see the same content, valid and visible JSON-LD, an explicit AI robots policy, llms.txt, Markdown mirrors and answer-first writing.
markdown-negotiationNo Markdown response for Accept: text/markdownllms-txt-missingNo /llms.txtllms-txt-error/llms.txt returns a server errorllms-txt-invalid/llms.txt doesn't follow the llms.txt formatllms-txt-not-linkedllms.txt exists but isn't linked from the home pagerobots-ai-policyAI crawler policy (allow/deny matrix from robots.txt)search-bots-blockedrobots.txt blocks AI search or user-triggered fetcherstraining-bots-blockedrobots.txt blocks AI training crawlers