Changing a Map Document's Description via python - Need Help

[MarkFox1]

So this should be a straight forward and simple code, but it's not working for me:

import arcpy

mxd = arcpy.mapping.MapDocument("G:/Projects/Phase II Project Location.mxd")
mxd.description = "Phase II"

When I run this script outside of ArcMap, then open the map document and check the Map Document Properties the map document's description does not get changed.

Am I missing something? I assumed this would be possible, yes?

Thanks for any help!

--Mark

[MathewCoyle]

You'll need this somewhere.

mxd.save()

[MarkFox1]

I knew it was something simple.

Thanks!
Mark