I adopt the mindset of docs are for humans, tests are for agents. They document formal dependencies and leave a measurable artifact behind. If you identify some behavior or transitive dep in your system, agents document it first with a test codifying the expected behavior. Tests are the source of truth about expected system behavior and you can convince agents to write decent behavioral tests if you ask them to with the right structure. Docs are now cheap and a render, not a long term thing. There is some token efficiency to consider, but still, they are quick and cheap if you don't understand some module or its purpose.