I don't believe there is such a document, mostly because usage tracking is a basic feature of the product itself. It's a bit like buying a car and asking for a document that says the engine is included in the new car you just bought.

If you have any licensing question, you should speak to your account manager: that's the person knowing exactly what kind of deal your company has with Oracle etc. And maybe that person will be willing to confirm you via email that usage tracking is a default feature of the product that is always part of it…