The reason for the behavior is the lack of messages for the ToolBar in the messages files. The overflow is generated with title="More Tools" which is causing a tooltip to appear when you hover the dots. This is how the overflow is generated in our source code:
A possible approach would be to change the title attribute value to fit your needs. Note that the ToolBar within other witgets such as the Editor, Spreadsheet etc has separate translations that can be used.
I hope that clears the matter. Let me know if you have any further questions.