The relative who asks for clearer plans may be trying to make joining you possible.

Requests for detail are often read as fussiness when they are really an attempt to say yes. Someone who needs to know the time, the address, whether there are stairs, how long it will run, may be arranging transport, medication, a carer or their own limited energy around your event. Vagueness is affordable for whoever is healthy and free, and expensive for everyone else. Being asked for specifics is usually a sign that someone wants to come.

When you invite people, give the practical details before they have to ask twice. If someone keeps asking, take it as interest rather than difficulty.