Maya
Open the Plug-in Manager (Windows > Settings/Preferences > Plug-in Manager) and load the AtomsAgents plugin. After loading the plugin you will find the AtomsAgents submenu under the Atoms menu.
Please note, AtomsMaya must be loaded before you can load the AtomsAgents plugin.
Houdini
There is no plug-in for Houdini. The menu will be automatically loaded inside Houdini.