When I edit a description of an event, I like the simple markdown editor, but if the description is too long and I want to use a markdown sign at the top, I have to scroll down all the description to the markdown menu to click on the markdown sign. Also, when I select a text at the bottom, the markdown menu is overlapped by the select text context menu.
So, I suggest to extend the keyboard for the calendar description by a single line of the markdown menu as most markdown editors already do.