The objective is clear.
Everybody has to participate.
There has to be assertive upward communication. The climber keeps the person (higher up) apprised of issues of concern.
The belayer (person higher up) has to keep track of how the climber is doing and provide support when there are problems or increased levels of uncertainty.
The climber has to make decisions and execute a plan off attack and suffer the consequences of a poor plan or poor execution. (Note: a fall by a climber puts the belayer at risk.)