Hi Ravan,
I must admit I am a bit surprised that as an instructor you are asking the meaning of "climb or descend visual". It is very elementry but crucial stuff.
Also a basic understanding of readback requirements is required by all pilots let alone an instructor. I suggest you have a good read of all of the AIP. If you dont know the meaning of this stuff maybe there is more info in there you need to brush up on? Its all pretty clear when you talk the time to read it slowly and think about what it says.
Not trying to give you a hard time but these questions should not be asked by a proffesional flight instructor, training the pilots of tomorrow.
Yours respectively,
Bulla