Thanks to @NikolausDemmel for making my point better than I did 
Yes, that is exactly what I was tryint to suggest.
if the command line tool wants to use the ROS interface to request
information from the daemon it again needs to wait for the discovery
phase to finish before it can do so.
Not necessarily. See http://eprosima-fast-rtps.readthedocs.io/en/latest/advanced.html#matching-endpoints-the-manual-way, for example.