I love your efforts to communicate more clearly with cats!!
If Bobi the Bad had access to a bell, it would never stop ringing. His vocal chords will never wear out, it seems, as he demands water FROM THE FAUCET, every faucet in the house, every morning, and all throughout the day. He has ways of letting me know exactly what he wants, and his demands escalate from there. NO BUTTON FOR BOBI.
Have you seen the video of the bell-ringing cat? Hilarious. Alas, I can't find the right one now.

and

Your cats are blessed to have you as their servant.