I stumbled upon this while testing one of our contrib tools.

It seems that the tool nav (left-side) menu tool URL when clicked the first time brings up the tool, that's correct. And when the tool nav tool is clicked again, it should perform a tool-reset, but the tool-reset URL that is formed is incorrect. For example (I super user'ed as msong), from the user's Home page:
here's the first click tool (Portfolio) URL:
https://localhost:8443/portal/site/~msong/tool/c24d784d-a8cc-4c6f-9eac-32a203b67007/listPresentation
here's the 'second' click tool (Portfolio) reset URL:
https://localhost:8443/portal/site/~msong/tool-reset/c24d784d-a8cc-4c6f-9eac-32a203b67007%20title=
You can see that there's a '%20title=' appended to the URL, which is incorrect and results in a blank page being displayed.

It turns out there's a syntax error in the portal module includePageNav.vm.