Blender Version
Broken: version: 2.80 (sub 74), branch: master, commit date: 2019-07-11 11:00, hash: rBd663048696b2
Worked: (optional)

Short description of error
The tooltip when hovering over the Corner Pin widget is identical to the one when hovering over the vector inputs, "Input value for an unconnected socket." While accurate for the vector inputs, I don't think it is correct for the widget.

Exact steps for others to reproduce the error

1. Create a new default file;
2. Go to the compositor;
3. Enable nodes;
4. Add a viewer node (this allows you to resize and test different sizes for the Corner Pin Gizmo);
5. Add a Corner Pin node;
6. See the Corner Pin widget tooltip.