Why not go public with the description?
As part of the search for the one suspect, French officials today carried out two raids today near the city of Lyon and in a small town north of Paris, based in part on U.S. intelligence information.
That should be pretty easy.....male of Arab descent, between 20 and 45. Oh yeah, the terrorists might get offended if we use such a description, so they probably won't. Can't be profiling now, can we?
Two reasons come to mind:
1. They don't have a good description.
2. Or, more likely, this 'French dropped the ball stuff' is disinformation. They know where he is an are following him to the folks upstairs. They don't want the folks upstairs spooked.