his functionality sounds like a known bug that is already logged for fixing in our internal system. It is observed when RadScheduler is bound to WebService - when the Enter button is pressed while the Advanced form is opened the inline form opens behind. If your case is the same please let me now and I will notify you in this thread as soon as the issue is fixed.
If your case is different please try to describe what are the steps to reproduce it.
As for the width and the height of the description field you can add the following css:
Hope this will be helpful.
All the best,
the Telerik team
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