I'm like you. I want to see the description in Windows Explorer. Here is the way I do it.
I found that Windows Explorer CAN show columns from the SW Summary tab information, instead of the Custom Property tab information. So, I used to simply do double entry for my description property. I would enter a description under the description custom property. And then I would copy and past it in the Title field on the Summary tab. Then I would show the title field as a column in Windows Explorer. I took it one step further and enter a basic project description in the Subject field and show that as well in W.E.
I have since found that a custom property can "link" to the information on the Summary tab (i.e. $PRP:"SW-Title"). So I changed my templates to have this link defaulted into the description custom property. This way I only have to enter the Title information on the Summary tab. This eliminates having to do double entry and the possibility of these two values not matching.
Linking the description custom property to the summary title information does have one drawback that I have found. I have recently been playing around with changing the tree display in assemblies to make it show the component descriptions. When the description property is linked, the description displayed in the assembly tree does not reflect the evaluated value. Instead it displays the link itself. I personally think this is a bug, or at best an oversight to the programmers.
There's one other weird thing about showing the Title and/or Subject columns in Windows Explorer. If the file is open in SW, the information will not be displayed. My guess is that this is a Windows thing.
Hope this helps...