Last prescription I got was antibiotics and steroids for an ear infection. The doctor indeed did give me dosage and schedule. Then the pharmacy also gave me instructions, and they were different. Seeing how each Doctor hopefully keeps up with their field and most likely can't really with others, I'd say the pharmacy instructions are usually safer unless the patient has specific circumstances only the prescribing doctor is aware of.

Sometimes the doctor will write something in latin abbreviations so you have to translate that and write it out in plain text but you typically want to make sure the entire directions can fit on a single label. If you just say "see attached directions" then you may not get paid for the prescription if their insurance audits it they will take back any payment they gave to the pharmacy because you dispensed incorrectly. They may also just write something unhelpful like, "as directed in discharge paperwork" or "to be dosed by pharmacy" or something really long that can't easily fit.

That said it's been several years since i have been there so there may have been more enhancements.