WCAG AA Empty Link for window resizer tooltip

I use the WAVE Web Accessibility Evaluation Toolbar extension. If you have the window resizer extension, the site seems to fail the WCAG AA Priority due to an empty link.
I have since discovered it is this extensions window resizer tooltip that is causing this error.
If at all possible it would be great to add anchor text (which can be visibly hidden). This will prevent the collision on the report and make this extension more accessible.