I have texted this with two devices:
With the Nexus 7, when you click in the Description box, the keyboard pops up and then pops back down again.
With the Sony Xperia Z1 Compact when you click in the Description box the keyboard does not appear at all.
In both cases this is using Chrome for Android. Currently the workaround is to use the BB Code editor.
This issue only affects Redactor on the Resource creation/editing screen. There are no issues with it in the rich text editor anywhere else in XenForo.