{
    "$schema": "http://json-schema.org/draft-07/schema#",
    "title": "AgentProgressUpdateData",
    "description": "Schema for the data part of an agent progress update signal.",
    "type": "object",
    "properties": {
        "type": {
            "type": "string",
            "const": "agent_progress_update",
            "description": "The constant type for this data part."
        },
        "status_text": {
            "type": "string",
            "description": "A human-readable progress message (e.g., 'Analyzing the report...')."
        }
    },
    "required": ["type", "status_text"]
}
