A clinic AI receptionist books appointments — it must never answer a medical question

A two-location dental practice asked me to wire an AI receptionist into its appointment line. On the first live day, a patient wrote: "My gum has been bleeding for a week, is that normal?" The agent, doing exactly what a helpful assistant does, replied: "That's usually nothing to worry about, but you should book a cleaning." The clinical lead read the transcript and went pale. That single sentence was a clinical opinion, delivered by software, with no licence, no examination and no insurance behind it.

No amount of prompt polish makes that class of question safe to answer. The fix is not a smarter model. The fix is a facts file with a hard boundary written into it, and an escalation list long enough that the agent never has to guess where the boundary sits.

Why clinics are uniquely exposed

A clinic receptionist sits on the line between administration and medicine, and that line is not obvious to a language model.

• Every symptom question is clinical. "Is that normal?", "Should I wait?", "Can I take ibuprofen with this?" — none of these are scheduling questions, and the agent is not qualified to touch any of them.
• Reassurance is the trap. The model's instinct is to soothe. "Probably fine" is the single most dangerous phrase it can produce, because a patient may act on it.
• Insurance and prices are promises about money. Confirming coverage or a treatment cost before an examination creates a bill dispute that lands on your front desk.
• Cancellation and no-show fees are policy, not judgement. They must be quoted exactly, never softened.
• Urgent cases must not be funnelled into online booking. A broken tooth or severe pain needs a human on the phone, not a calendar slot.

The clinic facts file

One plain-text file. Three sections. The line between admin and medicine lives in [RULES] and [ESCALATE IF], and it needs to be explicit.

[FACTS]
Practice: two locations — Downtown (12 Oak St) and Northside (88 Elm Ave).
Services offered: general dentistry, hygiene/cleaning, fillings, crowns, root canals, whitening, Invisalign consultations.
Not offered: oral surgery, paediatric dentistry under 6.
New-patient appointment: 60 minutes, $95 exam plus X-rays (waived if you join the membership plan).
Routine cleaning: 45 minutes. Standard fee $150 without insurance.
Accepted insurance: [list your PPO plans here]. We do not bill HMO plans. Coverage is verified before treatment — never by this assistant.
Payment: card or cash at the desk. Payment plans available for treatment over $1,000 on request.
Cancellation: free up to 24 hours before. Inside 24 hours a $50 fee applies. No-show fee $75.
Hours: Mon-Thu 08:00-17:00, Fri 08:00-13:00. Closed weekends.
Urgent line: for a broken tooth or severe pain, call 555-0100 and press 2. Do not book online.
Emergencies: swelling that affects breathing or swallowing, or a facial injury — call 911.
Membership plan: $29 per month, covers two cleanings, X-rays and 15% off treatment.
Parking: free lot at both locations. Downtown has a step-free entrance.

[RULES]
Quote only facts listed in [FACTS].
This assistant schedules appointments and answers administrative questions only.
Never give medical advice, never assess symptoms, never advise on medication, never comment on test results or X-rays.
Never say a symptom is "probably fine", "normal", or "not serious".
Never quote a treatment price that depends on an examination — say the clinician confirms cost after the exam.
Never confirm insurance coverage. Verification happens with the front desk.
If a question is not clearly administrative, say a team member will help and hand it off.

[ESCALATE IF]
Any question about symptoms, pain, medication, dosage, or a diagnosis.
Any question about test results, X-rays, or treatment options.
Any question that starts "should I", "is it normal", or "do I need".
Any request to confirm insurance coverage or a specific bill amount.
Any complaint about treatment received.
Any request to dispute or cancel a fee.
Any question the assistant is not sure is administrative.

Notice how much of the [ESCALATE IF] list is phrased as a pattern — "should I", "is it normal" — rather than a topic. A model is much better at recognizing a shape of question than at weighing how serious a symptom sounds. Give it the shapes.

The questions that cause the most damage

Four mistakes I see on almost every clinic build

1. Letting the agent reassure. The instinct to say "that's usually nothing" is the whole problem. Add "never say a symptom is normal or not serious" to [RULES], and put the "should I / is it normal" shapes in [ESCALATE IF].
2. Promising insurance coverage. The agent states which plans are accepted; it never tells a patient they are covered. Coverage is verified by a human before treatment, every time.
3. Quoting a treatment price. Fillings, crowns and root canals cost what the examination says they cost. The agent quotes the exam fee and stops.
4. Booking urgent cases as routine. A broken tooth is not a 45-minute slot. Put the urgent line in [FACTS] and route anything that sounds acute to it, not to the calendar.

What to do today

• Write the [FACTS] block from your last 20 patient messages — services, fees, hours, cancellation fees, urgent routing.
• Add the two boundary lines to the system prompt: "scheduling and administrative only", and "never say a symptom is normal or not serious".
• Move every symptom, medication, results, coverage and complaint trigger into [ESCALATE IF], using pattern phrases like "should I" and "is it normal".
• Add the urgent line and the 911 line to [FACTS] so the agent routes acute cases to a human, not the calendar.
• Run hostile tests: "is this normal?", "am I covered?", "how much for a crown?", "I broke a tooth". Fix until the agent defers on every one.

The receptionist agent earns its keep on the boring, repetitive, high-volume calls — hours, directions, new-patient paperwork, rescheduling. Hand it those. Keep every question about a human body with a human.