/**
 * Allows the agent to detect when a voicemail system is encountered.
 *
 * This tool should be invoked by the LLM when it detects that the call has been
 * answered by a voicemail system rather than a human. If a voicemail message
 * is configured, it will be played; otherwise the call will end immediately.
 */
export interface VoicemailDetectionToolConfig {
    /** Optional message to leave on voicemail when detected. If not provided, the call will end immediately when voicemail is detected. Supports dynamic variables (e.g., {{system__time}}, {{system__call_duration_secs}}, {{custom_variable}}). */
    voicemailMessage?: string;
}