Add text to tags to explain their context
Tags are great, but after a while you forget their exact meaning. You can end up with several similar tags that all mean the same thing. You can end up with tags where you haven't a clue what they are used for, especially when there are several people creating tags.
Give us the ability to add text to tags that explains what they are used for. If you hover your mouse over a tag in the main tag list the explanatory text should show up. There should be a separate 2 column view of tags that also displays the text for each tag. That will be a huge help when maintaining tags.