This is a fairly broad and at times, controversial subject.
IMO the preferred convention is a Noun or Noun Phrase, followed by "adjectives" that increase in specifics as you move to the right (primary identifier, secondary identifier). Building on your example above I would change the 1/2" to threadform (1/2-13 UNC), insert a Grade in front of it, add a length (X 1.25 LG), coating etc.
Key to this is to bear in mind that a Part Name can never fully specify something given that most systems have a character limit to the Name field.
The other thing to keep in mind is naming to support reuse, which means you need to differentiate while at the same time not precluding future uses of a component (So avoiding location and usage terms such as "UPPER" or "PRIMARY"). The worst example I have seen was "#2 O-RING".
Ideally, I would like to see PartsLink play a role in a Windchill based Naming Utility as alluded to above. The order and values of many of the Classification Nodes would drive the Name. This would also systematically avoid redundancies (thinking hardware here). The problem is the cost prohibitive PartsLink license model, which last time I looked into it seemed to suit a large organization with a dedicated parts classifier. A much larger group needs to create and name parts, and that (IMO) would make a PartsLink based naming utility cost prohibitive as is.