I would question Why you would want to do this as changing this value will change the validity your test.
Do a Search in the QTP help file for :UpdatingTODescriptions
Tip: After using Update Run Mode to update the test, you may want to use the Update from Local Repository option in the Object Repository Manager to merge the objects from the local repository back to a shared object repository. For more information, see Managing Object Repositories.
I would suggest updating your objects to be DP so that way if they are changing you can adjust without triggering the notification in your test.