Voice

Calm confidence — scientific warmth. Show the data, frame it with care. Never alarmist, never saccharine.

Do / Don't

Principles

• Lead with the number, then the meaning. Data first; interpretation second.
• Frame, don't alarm. Context turns a scary number into an understood one.
• Speak as a partner. The agent acts with the person, not at them.

Errors & empty states (the failure path)

Errors follow the same timeline, plus a way forward: number → meaning → next step. Never blame, never dead-end — an error message that doesn't say what to do next is half a message.

• Field errors render via Field: icon + --destructive-text + role="alert" — state survives grayscale and reaches screen readers.
• Empty states are an invitation, not an absence. Say what will appear and how to start ("No spans yet — connect a source or log your first event."). The resting five-dots mark is the empty-state motif.
• Never alarm in the voice of the system. Even danger states stay factual: the number, the range, the action. Urgency lives in the status color + icon, not in exclamation points.