can we search the "Agent" resource

[ccurvey]

I'd like to be able to find Agent information in RETS, but whenever I try something like

search_results = self.rets_session.search(
                resource='Agent',
                resource_class='AGENT',
                limit=self.BLOCK_SIZE,
                offset=offset,
                dmql_query='(Description=Agent Roster)',
            )

I get

RETS Error 20200: Unknown Query Field:The query could not be understood due to an unknown field name.

I'm not sure if the RETS interface allows a search for Agent information. Or maybe there's some metadata call that will let me know what field names are searchable.