As of 4.1.x, your page's description is not automatically generated, but manually set using the Description textbox on the Edit tab. Descriptions no longer use BB-Code. I've looked at the page in question and this page's description is showing this way because it is literally set this way. If the description is incorrect, you should manually update the field using the Edit tab. This change more matches the VaultWiki 3.x behavior that disappeared in 4.0.x.
Possibly it was set incorrectly back in the days when it was automatic (4.0.x), but since it is not automatic now, you will need to make the correction yourself.
When descriptions were automatic, they were not tracked separately in a page's history. So it is not possible to find out when the problem first occurred, but since the problematic code that generated the description is no longer in use anyway (unless to need to upgrade 4.0.0 RC 3 or lower, all now-unsupported versions), the underlying issue would be moot.