If you do so, please take a look at how flext provides hooks for xlet descriptions. I never looked at them more closely, but I guess those are simply not implemented in the Pd backend, but they are in Max and it would be cool to have it compatible.
Yes it's true. Flext provides the means to define the tooltip text, but as there's no respective api function in PD it doesn't do anything with it. Yet.
greetings, Thomas