GuidesAI agents
Every agent setting
Each section of the agent builder, every field in it, and what it changes on a call: defaults, limits and examples.
This page goes through the agent builder from top to bottom and says what each setting does to a real call. To create an agent and find your way around the builder, start with Set up your AI agent.
- Where
- AI Studio > Agents, then Open builder
- Saving
- Every change saves to a draft as you type. Callers get it when you publish
- Engines
- Settings marked Classic only don’t apply to Live agents. See Classic and Live
Some settings only exist on one kind of agent. Outbound agents add a Conversation guide, Variables, Voicemail and phone-menu navigation, covered in Build an outbound agent. Inbound agents have Phone & Routing. Outbound agents set a Max call length in minutes instead of a maximum duration in seconds.
Identity
| Field | What it changes |
|---|---|
| Agent name | Required, up to 100 characters. How the agent appears in Call Flows, reports and the agent list. An outbound agent also says it to call screeners |
| Business name | Up to 255 characters. The agent is told it answers calls for this business, and says it the way you write it. Leave it blank and the agent won’t name a business unless your instructions do |
| Engine | Classic or Live, shown for reference. It’s set when the agent is created and can’t be changed. See Classic and Live |
| Internal description | A note for your team, such as “Answers after-hours calls and takes repair requests”. The agent never sees it |
Voice
| Field | What it changes |
|---|---|
| Voice | Required. The voice callers hear. Filter by language, gender and Standard or Premium, and select the play button on a card to hear a sample |
| Speaking speed | Classic only. How fast the agent talks. Each voice has its own range, for example 0.60× to 1.50×, and starts at 1.00×. Some voices can’t change speed |
| Stability | Classic only, on voices that support it. Lower sounds more expressive and varied; higher sounds more even. Leave it untouched to use the voice’s own tuning |
| Similarity | Classic only, on voices that support it. How closely the speech sticks to the original voice. Higher can bring out flaws in the recording |
| Background sound | None, Office ambience, Café, Nature, Rain or Fireplace, played quietly under the agent’s voice once it answers |
| Background volume | 0 to 100%, 20% to start. How loud the sound is next to the agent’s voice |
Language comes from the voice. The language filter only narrows the list: the agent listens and speaks in the language of the voice you pick. Each agent speaks one language. To answer in two, build a second agent and send callers to it from a Phone Menu in your Call Flow.
Choosing a different voice resets the speed to that voice’s default and clears its style settings.
Greeting
The first thing every caller hears. Inbound agents speak as soon as they take the call.
| Field | What it changes |
|---|---|
| Greeting | Up to 1,000 characters, but keep it to one or two short sentences. Classic agents say it word for word. Live agents say it in their own words |
| Let the agent generate its own greeting | Classic only, off to start. On, the agent opens with a line of its own that introduces itself and asks how it can help, and the greeting box is ignored. A blank greeting does the same |
| Templates | Friendly check-in, Formal business, Casual sales, After-hours triage and Confirmation callback drop a starting greeting into the box. Picking one turns generated greetings off |
If your workspace plays a recording notice, callers hear it before the greeting.
Example. “Thanks for calling North Valley Heating. This is Sam. Are you calling about a repair, or something else?” It names the business so callers know they’re in the right place, and the question steers them to say why they’re calling.
Persona & Instructions
Who the agent is, how it talks and the rules it follows. These five fields matter most, so they have their own guide: Write your agent’s instructions.
| Field | What it changes |
|---|---|
| Role | One line, up to 200 characters, starting the instructions as “You are …” |
| Tone | Pick from Friendly, Professional, Concise, Warm, Direct, Empathetic, Patient and Confident, or add your own |
| Always | Rules for every call, one per line |
| Never | Things the agent must not do, one per line |
| Additional context | Facts and guidance: hours, service area, how to handle tricky cases |
| Response variability | Classic only, under Advanced. See below |
| Optimize | Rewrites the five fields to Clarify, Shorten or Add guardrails. You review the changes before they’re applied |
| Apply template | Replaces all five fields with a starting persona |
| Effective prompt | Shows the instructions the fields add up to |
Response variability
How much the agent’s wording changes from one call to the next, from 0 to 1. Consistent (up to 0.2) says the same thing the same way each time. Balanced sits in the middle, and Varied words things differently. It starts as Inherited (0.3).
It doesn’t make the agent friendlier or more detailed: that’s Tone. With Tools attached, keep it at 0.5 or below, because higher values make the agent use Tools less reliably.
Knowledge
Documents the agent answers from, such as a price list or FAQ. Attaching or removing a document applies to real calls straight away, without publishing. See Give your agent knowledge.
Business Tools
The Tools the agent can use on a call, each pinned to an exact published version. A newer version of a Tool reaches the agent only when you select Re-pin and publish. Changes here apply when you publish the agent. For each Tool you can change, for this agent only:
- Instructions: when and how to use it.
- Confirmation: what the agent checks with the caller before it runs.
- While the tool runs: what the agent says, the Minimum time before answering, Give up after (20 seconds to start) and a still-working line.
- What the caller hears for each result.
Call Handling
The agent picks from destinations you set up. It never dials a number the caller gives it.
Handoff
Off to start. Turn it on and add up to ten places the agent can send a caller: a ring group of your team, an outside number or a Call Flow. For each one, the Announcement, Ask before transferring, Play hold music while it rings, Ring for and If it doesn’t connect. See Settings for each destination.
End call
On to start. It decides whether the agent may hang up, and how it knows the call is over.
| Field | What it changes |
|---|---|
| Goodbye phrases | Words that tell the agent the caller may be done: goodbye, bye, have a good day, have a great day, take care and talk to you later to start. The agent reads the whole sentence, so “bye, actually one more thing” doesn’t end the call. If the caller says one and then stays quiet after the agent replies, the call ends |
| Farewell message | What the agent says last, up to 1,000 characters. Classic agents say it word for word; leave it blank to let the agent say goodbye in its own words |
| Idle retries | How many times the agent checks on a silent caller before it hangs up: 0 to 10, 2 to start. See Silence |
| Maximum call duration | The longest a call can last, from 30 seconds to 4 hours, 30 minutes to start. It counts from the start of the call, including any time in your Call Flow before the agent answered. At the limit, the agent says goodbye and ends the call |
Turn End call off and the agent can’t hang up: the caller ends the call, or the maximum duration does. A silent call then stays open after the idle retries instead of ending.
Behavior
How the agent listens and takes turns. On Live agents, the engine handles turn-taking itself, so only the idle prompt, the timing, the date and time, and Acknowledge while the caller is speaking appear.
Interruptions
Classic only. Interruption sensitivity sets how readily the agent stops talking when the caller speaks.
Interruption sensitivity
Never interrupt
Always finishes what it’s saying
Very resilient
Stops only when the caller keeps talking
Resilient
Stops for a clear word or two
Balanced (default)
Stops when the caller starts talking
Responsive
Stops quickly
Immediate
Stops at almost any sound
- Turn it down if background noise or the caller’s “mm-hm” keeps cutting the agent off.
- Turn it up if callers have to wait for the agent to finish before they can correct it.
Words that override this is on to start, with two lists of up to 50 words each:
- Words that never interrupt the agent: short acknowledgements like “mhm” or “okay”. If the caller says only one of these, the agent carries on.
- Words that always interrupt the agent: such as “stop” or “wait”. The agent stops at once, however hard it is to interrupt. While a Tool is running, what the caller says is answered along with the result instead.
Load preset fills both lists with starting words for a language. Turning the switch off keeps your words for later.
Knowing when the caller has finished
Classic only. Endpointing decides how long a pause means the caller is done talking.
| Field | What it changes |
|---|---|
| Endpointing | Adaptive (to start) learns each caller’s pace. Fixed always waits the same time |
| Minimum end-of-speech delay | The shortest pause that counts as finished: 250 to 1,000 ms, 400 to start |
| Maximum end-of-speech delay | The longest the agent waits: 500 to 3,000 ms, 2,000 to start |
If the agent talks over callers who pause to think, such as when reading out an account number, raise the minimum. If it feels slow to reply, lower the maximum. The minimum can’t be more than the maximum.
Silence
When the caller goes quiet, the agent checks on them, then gives up.
- 01
The caller stops talking
The agent waits for the No-input timeout: 30 seconds to start.
- 02
The agent says the idle prompt
“Are you still there?” This is the first idle retry.
- 03
Still nothing after another 30 seconds
It says the idle prompt again: the second retry.
- 04
Still nothing
The agent says goodbye and ends the call. With End call off, the call stays open.
| Field | Where | What it changes |
|---|---|---|
| Idle prompt | Behavior | What the agent says to a silent caller. Live agents say it in their own words |
| No-input timeout | Behavior > Advanced | How long the agent waits for the caller before the idle prompt: 3 to 60 seconds, 30 to start |
| Idle retries | Call Handling > End call | How many times it says the idle prompt before ending the call: 0 to 10, 2 to start |
Silence only counts once the agent has answered: not while the caller is in your Call Flow or ringing your team.
Date and time
Tell the agent the current date and time is on to start. The agent is told the weekday, date, time and time zone at the start of every call, so “can someone come Thursday?” is answered with the right date. Leave it on unless you have a reason not to.
Timezone uses your workspace’s time zone to start. Change it only for an agent that serves a different region.
Network status
Only for workspaces with the Outages App, for internet providers. See What your agents are told.
Boosted keywords
Classic only. Up to 50 words the agent should listen out for: product names, street and town names, technical terms, such as “Acme Pro” or “Quail Creek”. Add the words it mishears in your test calls.
Advanced
| Field | What it changes |
|---|---|
| No-input timeout | See Silence |
| Inject filler phrases during slow responses | Classic only, off to start. The agent says a short phrase such as “one moment” when a Tool is slow, unless the Tool just said its own line |
| Acknowledge while the caller is speaking | Off to start. The agent makes short sounds like “mhm” or “right” while the caller talks, as a person listening would |
| Background noise cancellation | Coming soon |
Phone & Routing
Inbound agents only. An agent doesn’t have its own phone number: callers reach it through a Call Flow. Add an AI Agent step to a flow and assign the flow to a number. See Build a Call Flow.
Versions
Every publish is kept, with its note and who published it. Compare any two versions field by field, and roll back to an older one. See Publish and roll back.
If something goes wrong
Something needs fixing first: the agent has no name or voice, its voice is for the other engine, the speed is outside the voice’s range, the minimum end-of-speech delay is more than the maximum, or Handoff is on with no destinations.
Speeds outside a voice’s range are refused on calls. Select Reset speed.
Lower Interruption sensitivity, and add the caller’s usual acknowledgements to Words that never interrupt the agent.
Raise the Minimum end-of-speech delay, or try Fixed endpointing.
Check Goodbye phrases for words callers use in passing, and raise Idle retries or the No-input timeout.
Add it to Boosted keywords (Classic only).
Changes stay in a draft until you select Publish. Only Knowledge applies straight away.
Last updated 18 Oct 2026