User Control Property Designer Properties

Is this of use to you? I am not into CF development, but it looks like you need to add some XML metadata to enable it:

http://blogs.msdn.com/bluecollar/archive/2007/02/08/adding-compact-framework-design-time-attributes-or-more-fun-with-textboxes.aspx

Interesting read.. Looks like a lot of design time support was stripped out of CF because you dont design them on the devices.. Which seems kinda weird to me.. Cant imagine using a handheld as a development rig!

Scroll down about half way for the good stuff ;)

DesignerCategory is used to say if the class is a form, component etc.

For full windows the attribute you want is:

[System.ComponentModel.Category("Custom")]

and for the description you can use [System.ComponentModel.Description("This is the description")]

To use both together:

[System.ComponentModel.Category("Custom"),System.ComponentModel.Description("This is the description")]

However this is part of system.dll which may be different for windows mobile.