JEI Compatability: Descriptions
When you have JEI installed you will also be able to read tooltips in the information category of JEI.
JEI Compatability: Compatible Items
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.
Tooltip
A screenshot of what an enchantment description tooltip looks like.