Documentation is only useful for agents if the source is unavailable, and if you are trying to save on tokens and trust that the docs are accurate.

If none of that is relevant to you, or rather accuracy is your concern, it's much better just to search the source code for your answers, from how to set up the application to configuration questions to troubleshooting. Bonus points if you strip out all the comments programmatically via linting before you even let the agent view the code, to avoid possible context poisoning.