No, you do not have to set up any data types.
As a user, when you are on a page that has a tool tip defined, position the mouse cursor over the field value for 5-6 seconds and the tip will 'pop-up'. To have a words appear next to a field show up all the time without using the mouse cursor, define a 'Hint' on the attribute field.
Please note in Classic PPM, the Studio 'Tool Tip' is designed as an instructional tip for editable fields only.
Therefore, the tool tip does not appear for fields that are locked or read only.