We've published a geoprocessing tool to a federated ArcGIS Portal, but would like to restrict access to it to a particular service running on a different server. I assume this kind of thing would be done by giving that service an API key for the geoprocessing service, but I can't find any documentation on how to do that or if it's even possible. Is using geoprocessing tools restricted to named user logins or is there a way a service can use them?
Thanks!