Remember the good ol' AutoExp.dat file from Visual Studio 6? It's the config file for how the debugger shows tooltips for various datatypes at debug time.

I've made it all these years with Visual Studio .NET not remembering about this gem. They've changed it slightly for VS.NET 2002/2003, but it's basically the same idea.

Look for mcee_cs.dat in the install dir\common7\packages\debugger directory. Fairly good notes at the top of the text file. Add your custom types at the bottom.

example:

<CallawayGolf.OrderTool.Order>=ID=<id> Acct=<accountName> PO=<poNum>

p.s. Looks like this needs a restart of the VS.NET IDE to take effect.