I'm looking at the suggested corrections for some artist names in a compilation. The tooltip shows some information, but not really enough to make a good decision. Two examples:

Set ARTIST in 1-15 C.I.D.m4a to "Uk Subs"
(as mentioned in a separate request, "Uk" should probably be "UK". In my metadata, it probably is)

Set ARTIST in 5-04 Damaged Goods.m4a to "Gang of Four"
(You're probably fixing title case by lowercasing "of," but maybe it's the wrong band altogether. I'd like to know what I'm changing from.

And while I'm here, the tooltip is a slow mechanism to see these details. It would certainly add some clutter to the interface, but I think seeing the changes would be huge.

Today, you show

Track name : Rule being triggered : Button describing edit (with tooltip)

I'd request

Track name : Rule being triggered : Button "Change" with before and after text in a "caption" below.