14 CFR 61.95 requires solo student pilots to have an endorsement to (a) fly through class B airspace or (b) takeoff/land at a class B airport. However, the requirements to get it are pretty vague:
(1) The student pilot has received both ground and flight training from an authorized instructor on that Class B airspace area, and the flight training was received in the specific Class B airspace area for which solo flight is authorized;
Is any particular content or amount of time expected, or is it at the CFI's sole discretion to decide when a given pilot is competent enough to endorse? Does the training itself need to be logged as such, separate from the endorsement?