I don't see why the GM would have to tell the players all these mechanics. Can't they just describe what happens while the player responds and as they interact with the player request the relevant skill rolls? I don't play 4E and don't know a lot about skill challenges, but I do something like this a lot, in chases for example, where I will have the players say what they do at various points and then request a skill roll based on that, and often have a set number of successes in mind for what results in getting away, catching someone, etc.