Voice and tone
Two customers can get the same facts from Costello and come away feeling completely differently — warm and looked-after, or efficient and a bit cold. The Voice & tone section is where you decide which it is. It controls how Costello introduces itself and the personality behind every reply.
Open Knowledge in the left-hand menu and scroll to the Style section (this is where voice and tone live).
The two settings
The introduction line
This is how Costello introduces itself at the start of a conversation. Keep it short and natural — it should sound like a friendly team member, not a robot announcing itself.
Good examples:
- "Hi, I'm the assistant at Glow Skin Clinic — how can I help?"
- "Hey! Thanks for messaging Lumière Aesthetics. What can I do for you?"
The tone descriptor
This is a short description of the personality you want. Costello uses it to set the mood of every reply — word choice, warmth, how chatty or brisk it is.
Worked examples
The descriptor genuinely changes the replies. Here's how the same answer shifts:
| Tone descriptor | The kind of reply it produces |
|---|---|
| Warm and professional | "Lovely to hear from you! Our HydraFacial is £95 and takes about 45 minutes. Would you like me to send you our booking link?" |
| Friendly and casual | "Ooh great choice — the HydraFacial's £95 and takes around 45 mins. Want me to pop you the booking link?" |
| Calm and clinical | "Our HydraFacial treatment is priced at £95 and takes approximately 45 minutes. I can share our booking link if you'd like to proceed." |
All three give the same facts. Only the feeling changes.
Matching your brand
A few tips for picking a descriptor that fits:
- Read your own Instagram captions or website copy out loud. Are they playful or measured? Match that.
- Think about your typical customer. A luxury clinic and a busy walk-in studio want different energies.
- Keep it to a few words. "Warm, reassuring, and never pushy" tells Costello plenty. A paragraph dilutes it.
- Avoid contradictions like "fun but formal" — pick the one that wins.
After saving, open the Playground and ask a few questions. If a reply feels off-brand, tweak a single word in your descriptor and try again. Small changes have a big effect.
After you save
Costello retrains automatically, so your new voice takes effect within about a minute.