How to write a VSIX extension in VB.NET that changes the tooltip of date variables?

I am working on a VSIX extension (named ChangeToolTipDate) in VB.NET for Visual Studio 2022 that changes the tooltip of date variables when debugging. I want to do this as a learning exercise and to make debugging easier. For example, when I hover the mouse over a date variable in the code editor, instead of showing the value of the variable, it should show “Hello”.

How can I do this step by step? And does anyone have or can share the complete project code?

I tried to search for a way to access and modify the tooltip of a variable in Visual Studio, but I couldn’t find any relevant documentation or examples.

I expected to find a method or property that would allow me to change the tooltip content of a variable programmatically, or at least a way to customize the tooltip format for date variables.