Booking direct is not a leap of faith, but a few questions up front make it a much smoother experience — and they are questions any decent operator will be pleased to answer.
Start with the total. Ask for the full price including cleaning, linen, any tourist tax and the security deposit, so you are comparing like with like against a platform quote. Then ask what the cancellation terms are and when the balance falls due.
Ask who you will be dealing with on the day of arrival, and how to reach them. Ask what happens if something breaks at eight in the evening. Finally, ask what the payment method is — a proper operator will use a secure hosted payment page, never a bank transfer to a personal account.
If the answers come back clearly and quickly, that tells you most of what you need to know about how the stay itself will go.