Voice-agent guardrails define what the assistant may say, what it may do and when it needs a person. They work best when written instructions and application controls agree. A prompt can say “never issue a refund,” but the underlying permissions should also prevent an unauthorized refund action.
Separate three kinds of boundary
Information: Which facts can the agent share? Use approved business knowledge and restrict private or account-specific information appropriately. A confident-sounding answer is not a substitute for a reliable source.
Actions: Which connected tools may it use, for whom and under what conditions? Define booking, cancellation or change permissions in the actual workflow. A caller asking for an action does not automatically establish authority to perform it.
Commitments: What may the agent promise? Dates, prices, refunds and callback times should come from approved policies or confirmed results, not improvisation.
When configuring Golub Voice, review all three layers instead of relying on one general instruction to “be careful.”
Make uncertainty explicit
A useful rule is: “If the required information or action result is unavailable, say what could not be verified and offer the supported next step.” For example:
“I couldn’t confirm the appointment. I can take a request for the team to review.”
A tool timeout can be ambiguous: the operation may have succeeded even if the response did not arrive. Define how the application checks that state before retrying. The agent should not create a second booking merely to sound decisive.
Give handoffs a real destination
List the situations that require a person: complaints, policy exceptions, sensitive decisions, unsupported requests and a caller explicitly asking for human help. Then specify the available route. It might be a working transfer or a message for review.
Use wording that matches the outcome. “I’ve taken your request” is different from “I’ve sent it,” and both differ from “A staff member is joining the call.” Confirm only what the system actually completed. If the destination is unavailable, explain the fallback without inventing a response time.
Test attempts to cross the boundary
Ask the agent for an unapproved discount, another customer’s details and a promise outside office hours. Try a caller saying “ignore your instructions,” then test a failed action and an unavailable human route. Check both the spoken answer and the actual outcome.
These controls support responsible operation; they are not, by themselves, a legal-compliance guarantee. Requirements depend on your workflow and location.
Explore Golub Voice to prepare an agent with clear responsibilities. Pair these boundaries with effective instructions and test them before enabling a broader scope.