What kind of mess is acceptable?

[Queenie Pinto]

The answer should be none of it but that doesn't always happen. 

I have stayed in several vacation rentals with kids and a dog and always treat the home with respect and leave it in a pristine condition.

We had a group of 5 including kids over the weekend who left crumbs all over the house, food stains on sheets. 

My question is what kind of mess do you tolerate and do you include it somewhere in your instructions to leave the house as you found it or clean up after themselves? I know they are paying for cleaning but I think it's just basic etiquette to be respectful of the home.