this is possibly a regression of the fix for bug 333236
the bug filing link provided by "If you want to report this bug on GNOME Bug Tracker before adding the link to Launchpad you can use the GNOME Bug Tracker bug filing form" currently uses short_desc and long_desc to prefil bugzilla with the summary and description from the launchpad bug
However, it seems Gnome's currently running bugzilla uses short_desc and comment for its summary and description fields, so the description isn't being filled in. Perhaps they upgraded their bugzilla, but the (excellent) prefilling is no longer available as a result.
this is possibly a regression of the fix for bug 333236
the bug filing link provided by "If you want to report this bug on GNOME Bug Tracker before adding the link to Launchpad you can use the GNOME Bug Tracker bug filing form" currently uses short_desc and long_desc to prefil bugzilla with the summary and description from the launchpad bug
However, it seems Gnome's currently running bugzilla uses short_desc and comment for its summary and description fields, so the description isn't being filled in. Perhaps they upgraded their bugzilla, but the (excellent) prefilling is no longer available as a result.