My T at least did not go into a lot of detailed questions on the phone. He simply wanted to know my main issue for seeing him and then saved all the details for first session. Even when you are really shy a good T should be able to lead the conversation and ask the right questions in the first session, and help you feel less anxious by the end of the session.
On another note, I used to think seeing two T's at once would be confusing and unhelpful to me, but when I started seeing a Pdoc for medication at the same time I was seeing T (who is a psychologist so couldn't write prescriptions) I found I liked having another T to go to when my regular T was confusing to me. I would compare it to having two parents. Like, "Hey, Mom, Dad said this... what the hell does that mean and is it true?" Then you get another view on it and sometimes it's the same view and sometimes it's just different by a little bit but it's helpful.