My agent, whenever changes are made, happily keeps those .md files up-to-date with newest changes.
Unless a LLM works truly as a compiler, there will be a drift between the code and the spec.
But yeah, I like to reference the docs so it can refresh his memory. But I may have had the .md files updated even if I didn't explicitly provide/ask for it, but a refactor that touched particular areas.
But yeah, my .md references others, it also maybe helps that my dir is named docs/ and it lists it somewhere in .md files... maybe its just the way it is structured helps infer agent what to do.