Service agent — provider-managed service account, used when one cloud service needs authorized access to resources created or managed by another service. Такие identities обычно создаются автоматически и используются для 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.