The DMFI Tool takes the appearance of a Ring and is granted to every new character.
Examining this item will also give further information about using various "DMFI" tools.
The ring itself can be used to change item names as well. Right click on the ring (or have it in your hotbar and left click) and select Use, then target an item to rename it.
The rename function allows you to also use special characters such as bold, italics, and colours.
Special Characters are convered under Special Text Formatting