atos home visit by doctor

Hi, could any body please give me information about what to expect from the home visit from an atos Dr, i suffer with fibromyalgia and border line personality traits, the is the second time i have applied for dla, the first one was a year ago and i am waiting for a tribunal date, i have recieved all the evidence back from the tribunal and am not sure why, and am still waiting for the date.
The atos Dr is coming in a week, i thought this was quite fast as i only posted the new claim about 3 weeks ago. Any information or tips please, thanks in advance Judith x