Creating a documentation of a tool or automated application is necessary. If we will not provide proper help to end-users then user will face difficulties in using your application.
If we will create a separate documentation to how to use the application then user needs to open documentation file to understand the user-interface. If we can add guidelines in the same file then it will be easy for user to get help at real-time.
Pop-up help provides the best solution of guidelines so that user can get help on click of button.