Does anyone charge a "call out fee"?

[Colin Ross]

Hi all - I just got my first rental property, and I am writing my rental agreement. I was thinking about adding in a "call out fee" clause, which basically says that if they call me to the property, they pay me $20 (reduce frivolous calls) which will be reimbursed if the thing that they called about is something that should be covered by me. I did some quick searching, and didn't find anything obvious. Is this something that people do? How would you write the clause in the agreement?

Many thanks

Colin