I think it's fairly useful to give direction to whoever is supporting you.
I would recommend making two separate ones. One for your support person reminding them of everything you've practised/discussed and one for the midwives which is more basic.
For the midwife one, try to keep it less than one page, bullet pointed and as succinct as possible.
Don't include anything that's already hospital policy as it's just waffle. So things like intermittent monitoring, no episiotomy unless necessary etc will likely be unnecessary as these are standard. You can always check with your midwife at an appointment near the birth if you need to clarify policy.
Do include preference on vitamin k, cord clamping and whether you want the injection for the placenta. Those are the things I've been asked or which might differ from normal policy.
Do include any important info like allergies, phobias, language barriers etc.
I think it's helpful to include whether you're an independent person who would prefer to be left alone as much as possible vs somebody who values direction and coaching, and whether information on things like how dilated you are or what they are thinking is something you'd like to know, or whether you're a more ignorance is bliss unless you need me to do something kind of person. Bear in mind this may change on the day, but generally whichever approach you favour in life is likely to be appropriate in labour. And then a general idea of what your rough plan is for pain relief, but there's no need for huge detail, just something like "non medical options for pain relief as long as possible" or "epidural please ASAP" or "gas and air but no opiates" or whatever. You will be able to discuss the various options at the time.
If you want to have access to a birth pool, ask for this verbally as soon as you get to hospital. If it's in use, it's worth asking again in a few hours in case the lady using it has finished or changed her mind.
If there's anything that's particularly important to you in an adverse situation, include this in a separate section at the end.