HCM Data Loader supports bulk uploading for Agents for Oracle recruiting cloud. Currently, there is no HDL support for loading Agencies. And idea is already submitted for same:
https://community.oracle.com/customerconnect/discussion/666039/hcm-data-loader-support-for-loading-agencies-in-recruiting-cloud#latest
Coming to Agents bulk upload, you can used below HDL:
METADATA|Agent|EmailAddress|AgencyName|AgentNotes|FirstName|LastName|StatusCode|SourceSystemId|SourceSystemOwner
MERGE|Agent|Agency.Name@invalidemail.com|ExecFinder|67 High Street, London|Agency|Name|Active|ExecFinder.Agent1|HRC_SQLLOADER
METADATA|AgentContext|EmailAddress|Username|SourceSystemId|SourceSystemOwner
MERGE|AgentContext|Agency.Name@invalidemail.com|Agency.Name|ExecFinder.Agent1|HRC_SQLLOADER
METADATA|AgentContextLocation|EmailAddress|Username|LocationName|SourceSystemId|SourceSystemOwner
MERGE|AgentContextLocation|Agency.Name@invalidemail.com|Agency.Name|Germany|ExecFinder.Agent1-Germany|HRC_SQLLOADER