When you're running a site through Visual Studio's internal web server, Fiddler doesn't pick up the traffic. The help documentation gives a few tips for working around this problem, but the one that worked for me I found on Loren Halvorson's blog: add a dot [.] after localhost and before the port colon.
I recently received some link-love from Pete Aven (Twitter, Blog) for some XQuery and MarkLogic Server posts I have here. The posts are kind of out-dated at this point, but I leave them up in case they help someone out. When I was just starting out, this kind of information was invaluable to me so I'm just trying to pay it forward.
I'm currently on a big SQL Server based project and my last MarkLogic project had some hellish deadlines that didn't leave much time for posting newer bits. With a little luck the next project I have lined up will bring me back into the XQuery/MarkLogic fold!
TinyGet is still a tool I use for some quick and dirty load testing, but I never needed to pass it URL parameters before. Simply adding an amerpsand was failing. The trick is escape it with the ^ character.