I have made the tool more generic. You can control the scope of the tool, Project, current folder and subfolders or current folder only. You can also choose to prepend, append or apply the text to the image's comment field. Not sure if anyone else would find it useful, but that doesn't matter.
The new version is posted
here
If you do use this version you will need to deleted the tools preference file (for projects it has already been used on). It is in the project's root folder under the hidden .jalbum folder and is called defaultTextToCommentsSettings.properties