I think in this instance it's also a matter of tools. Visual Studio/Visual Assist would have been able to find the class definition, and that's where the comment would go. For cscope it's a matter of configuration, which should be auto-generated by the build tool.

If the class is being used, then the definition has got to be somewhere, hopefully in a header. It's simply a file that is included somewhere. And it will be human readable. There is no magic.

The class definitions were not in any file. That was the entire point. They didn't exist at all except as transient build artifacts.