I once had a medical procedure preceded by this oral warning by the doctor: "Are there risks? Sure. But the risk is a lot greater if we don't do it." Concise and helpful; why say more? (Rhetorical question--you have to say more, even if it's less useful, or the lawyers will get you. Someday, somewhere, a lawyer is going to base a case on a warning's being too strong, and so discouraging the plaintiff from doing something that would have helped.)