I always ask the age when someone contacts me for the first time, to give me an idea of who I am going to meet, definitely.
But I don't ask for more details, no. Some people in their 30s don't want penetration, or some in their 40s have ED because of medication, and it's perfectly fine. Sex is not a choreography that I learnt by heart, it's a play time that is tailored to each person I see. Usually, they will tell me in person if they can come or not, if they have ED, but otherwise, I don't need to know in advance, I am always prepared to play in a way that will satisfy the person in front of me. But most older people I see are people like you and me, mobile people who can shower by themselves, who like to go out to the restaurant in good company and to have sex.
I must add that people with disabilities will tell you in advance of their use of a wheelchair or a cane just to make sure your space is adapted, or if it's the reason you have to go to them. Age here is unrelated.