You kind of have a choice here. You could either choose to stick to only the stuff you think is most important and give descriptions, or you could choose to list everything and not give descriptions. Which you choose depends on your situation. If you have a lot of random hobbies that don't take up a lot of time and aren't particularly interesting (such as playing volleyball in a rec league for 2 hours each week) and some of your more important things are things that people might not really know what they are just from reading the name of the activity, then you should probably choose the first approach. If you think all of your activities are pretty important and they're all pretty self-explanatory, then the second approach is probably better.
