Pressing Accept or Decline on the notification never answers by itself. Kemble opens on the request and shows the person’s picture, name and username, the note they wrote, and the friends and communities you share. One button confirms the answer you chose, the other answer is a press away, and Cancel leaves the request waiting. Tapping the notification itself opens the same view with both answers offered.
If the request was already answered on another device, withdrawn, or you are already friends, Kemble says so and sends nothing. When message previews are off, the lock screen says only “Friend request”, with no name.