A customer-facing assistant is a representative of the business. That sets a higher bar than a personal productivity tool: it must be constrained to information the business has actually published, and it must be willing to hand off.
In practice that means grounding answers in a defined knowledge source, refusing categories of question outright — legal advice, guarantees, anything about security posture — and routing to a human when confidence is low.
The measure of a good assistant is not how many questions it answers. It is how few of its answers have to be corrected.