A screenshot of what an enchantment description tooltip looks like.
This is what the tooltip looks like in game.
When you have JEI installed you will also be able to read tooltips in the information category of JEI.
When JEI is installed you can see additional enchantment information such as a list of all items that can be enchanted by a given enchantment. Hovering over the items will also tell you how to apply the enchantment to that item.