Dont rely on your agent for anything - unfortunately they are not experts in any area, even in finding a 'suitable' tenant. IME they just want to give you anyone, so always check, how many people will actually be living at the house, what exactly their jobs are, whether they've rented before, how old, no pets, why they want your house, for how long? You are trying to get a responsible, long term tenant and getting the right tenant is critical to whether, or not, this will work.
You say above that you're left with £52 a month - but with the correct tax deduction you are just about breaking even. You will have to fund repairs, gas safety, voids, tenant find fees, 6 monthly inspections - assuming your tenant stays 12 months you're probably going to have to put £1000pa in. With interest rates estimated to return to 5% in a couple of years it could be double that.
It doesnt make it a bad idea, you just need to be prepared.