The IETF currently has somewhere around 8 competing drafts for standardizing agent discovery -- agents.txt, ARDP, AID, AINS, and others. The original agents.txt draft actually expires April 10, so that whole space is in flux. Until there's a standard way to discover servers across protocols, any control plane is limited to whatever servers you manually configure.
The agent discoverability is next in line.
Great feedback as well so thanks for commenting!