How a funny text story gets its laugh
A joke in a chat is a setup the reader sees coming and a last reply they did not. Every story here opens on something dull (a walk update, a plant check-in, a game lobby) so the turn has something to break.
Keep each message short enough to read in a second. In a chat the pause before a reply is part of the timing, so a one-word answer like “WHAT” can be the funniest line in the story.