Get it in writing.
Verbal promises are not worth the paper they are written on.
Make sure to include A minimum amount of time and notice to cancel the contract, as well as a requirement for complaints on either side needing to also be written and signed by the other party.
Add a rule to extend the required tasks as new things come up in writing, And add in a disclaimer that if it's not written down and signed by both parties, it's not a requirement.
Include an out for failure to perform on both sides, on your roommates side for failing to pay the rent and on your side for failing to do the housework to a satisfactory standard.
Give yourself both easy outs that give you each enough time to adjust if something happens. And also write down on the paper that maintaining your friendship is the reason you're writing the contract.
I know it sounds silly, but Contracts like this are meant to help establish the rules and make things easier.
In many parts of America, $1750 a month after taxes is like a part-time job. In other parts of America, $1750 a month is a full-time job.
Make sure that your roommate does not feel like they are overpaying for what they get, or that they have bitten off more than they can chew.
I would say that you should include something along the lines of If your roommate cannot or does not want to continue the contract, they have to give you enough time, (I would say like six weeks) to start paying rent again, And include that during that change over time, you will still continue to perform the work you have agreed to in the contract.
Either which way it goes, best of luck.