(covers information from several alternate timelines)
A temporal agent was an operative working for a faction in the Temporal Cold War based in the 31st century. Enforcing the Temporal Accord, the agents worked to protect the timeline from temporal incursions, and monitor authorized time travel activities.
The only identified temporal agent was Daniels, who infiltrated Enterprise NX-01 in 2151, posing as a steward. Daniels would continue to interact with the Enterprise crew, working with them to oppose the plans of the Cabal and other Cold War factions, including Vosk, a Na'kuhl temporal agent. Daniels carried a suite of 31st century equipment, which might have been standard issue for temporal agents, e.g., a holographic database, a Temporal Observatory, and an interphase device that allowed the user to pass through solid objects. (ENT: "Cold Front", "The Expanse", "Carpenter Street", "Storm Front", "Storm Front, Part II")