Which time?
1911-1915 he was pretty good. Supervised the changeover from oil to coal power in capital ships and pushed throught he Queen Elizabeths. Admittedly Gallipoli was a disaster and he had to resign over it, since he was the most visible proponent of it. That said, he did well in getting the RN ready for WWI and was instrumental int he development of the tank, so I'd grade him passing personally.
September 1939-June1940 he got hamstrung by Chamberlain over protecting Norway and was unable to move the fleet into Norwegian Waters to smash the German invasion. Not his fault there. also when he got back int he office, the war had broken out so his ability to modernize and refurbish the RN was pretty much secondary to the need for warships to be on station rather than in drydock.