I'm seeing this same error with 10.2.1, seems like a bug, here's the result from the describe function
>>> for fld in desc.fields:
... print(fld.name + " " + fld.type)
...
OBJECTID OID
COMMENTS String
NAME String
YEARESTABLISHED Date
MXPARENTLOC String
CREATEEDITOR String
CREATEDATE Date
LASTEDITOR String
LASTEDITDATE Date
Shape Geometry
GlobalID SmallInteger
Shape.STArea() Double
Shape.STLength() Double
>>>
but the field shows as a GlobalId type in ArcCatalog