viraptor parent
You don't have to reexplain the business context. Save it to the mdc file if it's important. The added benefit is that the next real person looking at the code can also use that to learn - it's actually cool for having good up to date documentation is now an asset.
Do you find your agent actually respecting the mdc file? I don’t.
There should be no difference between the mdc and the text in the prompt. Try something drastic like "All of responses should be in Chinese". If it doesn't happen, they're not included correctly. Otherwise, yeah, they work modulo the usual issues of prompt adherence.