Discovery, qualification and pitch are sequenced for a buyer arriving uninformed. The buyer who now arrives has done the discovery, assembled a shortlist, and formed expectations. Being taken back through it reads as a lack of respect for their time.
What to do instead
Establish what they have already concluded and where those conclusions came from. Some will be wrong, and the useful part of the conversation is finding which. That is diagnosis rather than qualification, and it is the only version of a first call that gives the buyer something.
What it must not attempt
Closing. A first conversation that tries to close a buyer who has not finished deciding converts the doubt into a polite exit. Writing down what the conversation must establish, and what it is not allowed to attempt, is what keeps it from drifting back into a pitch under pressure.
It also makes the call reviewable. A conversation assessed against a written standard can be improved by someone who was not in it.