Agility exercise is an exercise that increases your speed and co-ordination. So at first agility exercise can be tiresome, but once you build up your speed it should not be as tiresome.
A couple examples of agility exercises are shuttle runs and jump box drills. Shuttle runs are basically sprints between markers, and there are many different types including side-to-side runs,...
Agility exercises will help you with endurance and speed. They will also hgelp you with reaction times. They are great exercises for any athelete to use to improve their skills.
You can do squats which will help you with squatting down and hitting the ball. Jump squats will be even better if you have to jump in your position in volleyball.