I think James hit the nail on the head.
If a Photographer is looking to book a model they will be very open and honest about the shoot and its details even if its on a hush hush IE a new unseen line of fashion Shoot, giving the info such has wear and when it will be published isnt going to harm anything! after all the photographer
MUA and a whole line of people will know all this.
also you have the right to request to see a copy of the model release form or contract if its going to be more than one time shoot in advance of the shoot.
also as James has said always Confirm for your self that they'er working for or on be-half of the mag or company that they say they are.
oldest line in the book is Im looking for models for a shoot for so and so Mag! or a New mag thats going to be launched very soon
(the new mag one lets them play on the so i cant give out much info crap)
Best wishes
James.