Why do I have to say "climbing TO" or "descending TO". I mean its just unwarranted waffle. If you want to achieve better radio efficiency stick to the main words, it's not a Shakespeare recital. I would have the call as just "ABC Climb Level 320" - "Climbing Level 220 ABC".
From memory the word "to" in a clearance to climb or descend was dropped as a result of a Flying Tiger freighter accident on landing in Kuala Lumpur in the late 80's.
This
extract from Wikipedia says it as well as I can:
(ATC) radioed to the flight, "Tiger 66, descend two four zero zero (about 2,400 ft (730 m)), cleared for NDB approach runway 33." Captain Halpin, who interpreted it as "descend to four zero zero" replied with, "Okay, four zero zero" (meaning 400 ft (120 m) above sea level, which was 2,000 ft (610 m) too low). The CVR[9] also revealed several communication errors made by the flight crew prior to this miscommunication and a general casual nature of the captain, who was the pilot-not-flying on this particular leg of the trip.
The aircraft flew into the ground at 437ft above sea level and well short of the runway, despite numerous GPWS warnings on the approach.