Can an AI answer a law firm's phone without giving legal advice?

What must an assistant on a law firm line refuse?

Legal advice and opinions, any prediction about how a matter might turn out, fee and retainer amounts, whether the firm will take the case, and substantive detail before a conflict check.

Callers ask all five, usually in the first minute, and often phrased so casually that a helpful system will answer without noticing it has.

How do I know a refusal is real?

Ask whether it is enforced by a test the agent must pass before deployment, or written as an instruction in a prompt. Ask what happens after the underlying model is updated.

Prompt instructions get ignored under pressure from a persistent caller. A test that has to pass before the agent goes live, and again after every model change, does not quietly stop applying.

Is it worth it at all for a small firm?

It depends entirely on whether missed enquiries are costing you work. If the phone is answered reliably during hours and enquiries are followed up, the case is weak.