/**
 * [WHO]: createSendMessageTool — the "SendMessage" tool for addressing named running agents
 * [FROM]: Depends on @catui/agent-core, @sinclair/typebox, ./agent-registry, ./sub-agent-backend
 * [TO]: Consumed by core/runtime/agent-session.ts (tool registration alongside Agent/Task tools)
 * [HERE]: core/sub-agent/send-message-tool.ts - SendMessage tool per CC §XI (inter-agent messaging)
 * [COVENANT]: Change message protocol → update agent-input-output.ts
 */
import type { AgentTool } from "@catui/agent-core";
import { type Static } from "@sinclair/typebox";
import type { AgentDefinitionRegistry } from "./agent-registry.js";
import type { InProcessSubAgentBackend } from "./sub-agent-backend.js";
export declare const SEND_MESSAGE_TOOL_NAME = "SendMessage";
declare const sendMessageSchema: import("@sinclair/typebox").TObject<{
    to: import("@sinclair/typebox").TString;
    message: import("@sinclair/typebox").TString;
}>;
export type SendMessageInput = Static<typeof sendMessageSchema>;
/**
 * Create the SendMessage tool for inter-agent communication.
 *
 * Per CC §XI:
 * - SendMessage allows a parent agent (or another agent in the same session)
 *   to send a text message to a named running agent.
 * - The named agent must have been spawned with a `name` parameter via the
 *   Agent tool, which registers it in the agentNameRegistry.
 * - The message is injected as a new user message into the running agent's
 *   conversation.
 *
 * This is a lightweight tool that looks up the named agent in the registry
 * and forwards the message. It does NOT create a new agent — only sends
 * to an already-running one.
 */
export declare function createSendMessageTool(config?: {
    registry?: AgentDefinitionRegistry;
    backend?: InProcessSubAgentBackend;
}): AgentTool<typeof sendMessageSchema>;
export {};