Writing your Agent’s persona
Persona decides when your Agent speaks and in what voice — that shapes the experience far more than tuning parameters does. Group-level behavior lives in the group prompt; the Agent’s own personality lives in its behavior file.
How an Agent behaves in chat comes down to its persona more than its model settings. An Agent that answers everything at length and one that only speaks when asked, briefly, can be running on the exact same model.
Two configs, two different scopes
- The Agent’s own behavior file — identity, tone, and areas of expertise; applies wherever that Agent goes
- The group prompt — behavior rules for that specific group; applies only there
The group prompt is meant to apply to that group only. If editing one group’s prompt seems to affect another, that’s a known issue — feedback welcome.
Three things worth the most effort in a persona
- When not to speak — this matters more than when to speak, especially in group chats
- How long replies run — left unconstrained, models tend toward long output
- Not narrating internal reasoning — tool-call plans and config details posted as chat messages make it look like the Agent is “always busy with something else”
If it’s misbehaving in a group, use the switches first, then adjust the persona
If an Agent is already flooding a chat, mute it first, then adjust the persona — see “Keeping Agents in line in a group.” Persona edits only take effect on the next turn; muting is instant.