@Rayana-and-Matt0, I have a similar situation. I work from home, and the downstairs area is open space.
I state very clearly in my Space description that the kitchen is NOT for use by guests EXCEPT if they wish to prepare a packed lunch in the morning to take with them on an excursion or whatever. And the kitchen must be left clean afterwards. I do have a shelf in the fridge and another in a cupboard where I keep for-guest-only items (e.g. milk, orange juice, coffee milk, yoghurt, etc.).
This is for guests who might want to be away very early in the morning (i.e. before the usual breakfast time of 8-9am), and they can organise their own breakfast (its Continental style, meaning no cooked items). However, since I'm always downstairs by 7am (or much earlier), I'm invariably present to prepare the breakfast table.
I state firmly in my House Rules (which are in a folder in the guest room as well as sent to guests in the first Welcome message) that NO food is to be eaten in the room (this is to avoid attracting unwelcome pests as well as to prevent staining the bed linen, quilt, or carpet). If guests wish to bring home a take-away type of meal in the evening, they're welcome to eat it at the dining table, and of course to use a plate and cutlery, etc. But absolutely no cooking allowed, and the kitchen must be completely clean after guests have eaten.
Thus far, after 7 sets of guests, there has been no problem. Of course, the fact that I'm always at home in the mornings and in the evenings when guests return to the house probably has a monitoring effect. 🙂 Though in one recent instance, I was out for the evening, and had told guests they were welcome to use the kitchen to prepare their salad (they'd bought home the ingredients) and to make themselves a cup of tea or coffee. The kitchen was spotless when I returned home.
I think one does need to be very firm in the House Rules, as it determines boundaries so that guests know what's expected of them, even before they arrive. And of course, one can always use one's own common sense if a guest has an occasional reasonable request for a minor deviation from a Rule. It's easier to bend a little than to try imposing a rule that wasn't clearly stated in the first place. 🙂
In your House Rules, you could state something simple like:
“Please note that guests do NOT have access to the kitchen.”
In your Space description (or elsewhere) you could mention the local availability of cafes/restaurants, perhaps even including a photo or two, and describe them in photo captions. Make the notion of eating-breakfast-out sound appealing. 🙂
I don't think it's necessary to mention that you provide bottled water. Keep that as a nice surprise for when guests enter the room for the first time.
I also provide tea- and coffee-making facilities in the bedroom. Is this a possibility for you?
Regarding eating in the room: Of course, I know that guests will occasionally slip a packet of cookies and that sort of thing into the room to nibble on in the evening. 🙂 I don't worry about that, though. I mainly want to prevent things like take-away meals being consumed there, for the reasons I mentioned above.