Tool
constructor(messages: List<ModelMessage> = emptyList(), streamingAssistantText: String = "", currentToolCalls: List<ContentPart.ToolCall> = emptyList(), pendingApprovals: List<PendingApproval> = emptyList(), isStreaming: Boolean = false, isModelLoading: Boolean = false, error: String? = null, totalSteps: Int = 0, lastFinishReason: FinishReason? = null)