Warning

So you are looking for a Toller?
A few things to remember:

Always ask to see the pedigree of both parents, at least the mother's and a copy of the father's. See how much they are related.
Ask for a conformation in writing that the puppies will have an official FCI-pedigree.
Look at the age of the parents.
The bitch should at least be 2 years old, and the studdog over a year.
Make sure the puppies grow up in the house, living with the family. Tollerpuppies (in fact every puppy) need a lot of socialising, and getting used to house-life.
Keep an eye on the mother, if she is shy or nervous, the puppies will copy that behaviour.
Demand to see the official hipcertificates from both parents. Don't let any body fool you. The fact that the grandparents were okay, doesn't automaticly mean that the parents are. They have to have official documents to prove that.
Same thing goes for eyetests. Ask to see the official certificates, and also ask about the parents Optigen-pra-dna status.
When buying a puppy ask for thebuyers/sellers contract and garanties IN WRITING.
If, for any reason you don't get to see all this, or some-one does't want or can't tell and show you these, just walk away and try to find a real breeder, some-one ho cares for the breed and health.

Good luck un your search for a healthy and well-socialised puppy.