If you would like to modify or remove the tooltip for a field, you just need to modify the text in the 'Inline Help' textbox in the settings of that field. As an example, you may have a tooltip on the Email field of the User entity, that says “The user's email address.” and you would like it to read “The user's email address. Must be formatted as someone@example.com” for clarification.
To Modify or Remove Field Tooltips
Note: The content within certain tooltips may be filled in automatically the first time you sync a field from Salesforce. If the tooltip you wish to modify is on a field within a Salesforce entity, open the entity via Setup > Salesforce.
1. Navigate to Setup > Entities and find the desired entity, then open it.
2. Click Edit, then remove or modify the text from the Inline Help box and click Save.