Kruijswijk is one of the worst descenders among the GC contenders imo, and I'm not saying this solely based on 2016 Agnello. He was awful on Grosse Schiedegg at Tour de Suisse 2011 ( I may be wrong about this though ) and I also remember him almost crashing into Majka on the descent of Pian del Falco at 2016 Giro.I honestly have Kruijswijk as worse at everything than Nibali, though he has put out some surprising ITTs a few times. But the main thing about Kruijswijk is he's such a liability going down there is no way Nibali can't destroy him in that alone.
( Also an interesting note about 2016 Giro is that whenever one of Nibali, Valverde and Chavez made a little dig on a descent, that trio ( Nibali-Valverde-Chavez ) formed up and dropped the rest before sitting down. And on the descent of Agnello, Kruijswijk crashed trying to follow Nibali and Chavez. )