Just a note - this thread is getting really fragmented. It is best to create a new thread when the topic is being changed.
Here is a response to Christopher. This following code updates the mxd.description
import arcpy, os
parentDir = r"C:\Demos\MapAutomation\SaveToPDF"
for (path, dirs, files) in os.walk(parentDir):
>>for filename in files:
>>>>if filename.lower().endswith(".mxd"):
>>>>>>mxd = arcpy.mapping.MapDocument(os.path.join(path, filename))
>>>>>>print mxd.filePath
>>>>>>mxd.description = "python test"
>>>>>>mxd.save()
Get rid of the ">>" symbols.
Hope this helps,
Jeff