A service agent is a provider-managed service account used when one cloud service needs authorized access to resources created or managed by another service. Such identities are commonly created automatically and used to perform service operations under controlled permissions.
A service agent refers to a Google-managed service account. It's utilized when a service requires access to resources created by a different service. For instance, when Dataflow or Dataproc services need to create instances during runtime or when a Cloud Function wants to use the Key Management Service (KMS) to protect the Cloud Function. Service agents are created automatically by Google Cloud when a service requires them. They are typically used to manage access to resources and perform various tasks on behalf of the service. For more information, see Service agents.