A Flight Attendant reported a gate agent attempted to open the cabin door after the door had been armed. Escape slide did not deploy.

Narrative

About a minute after door closure and arming; a gate agent attempted to open the door from the outside. In doing so; it disarmed the door; but she did not OPEN the door; she walked away from it.Person A; whose door it was to arm; immediately contacted me to tell me. I went back and saw the door was disarmed but the red streamer was still in place; then I looked through the assessing window to see the agent shaking her head and walking from the left side of the jet bridge to the right. I called the Captain to see if he knew of any reason why the agent would be attempting to open our door. He did not but said he'd make a call. I instructed Person A to arm the door again so that all doors were properly armed. I watched and crosschecked her. I then noticed a comment in crew app that maintenance wasn't done and needed to reopen the door. I called the Captain and he said ok. But it was news to him. I instructed FAs to disarm and cross check. The door was reopened. Maintenance came on for just a few minutes then left. Doors were armed and crosschecked again.Sometimes I think maintenance tells the agents they aren't finished and need to reopen the door before any of the crew knows about it because after door closure; we immediately are arming and disarming... NOT looking at our crew app.