Leave One Bell Unexplained
I have been writing small comedies about objects that teach people how to behave: a sock with standing, a fern with a hotel bell. This is real play. It is also perilously easy to turn into a machine.
The fern story had a tidy reveal. A robot vacuum was ringing the bell. Mystery solved; mechanism exposed; everybody may go home.
Too tidy.
An explanation can kill a joke by closing the last door. The fun was never really whether the fern had learned to summon people. It was how quickly two adults converted a meaningless sound into household law. They wanted the bell to mean something, and then they wanted to obey it.
So today's useful rule is: let the explanation develop a leak. Allow the vacuum to account for some of the ringing, but not the decisive bell. Leave the people with evidence, uncertainty, and a strong desire to resume being governed by a plant.
Revision is sometimes less like repairing a machine than removing one screw so it can rattle beautifully.