/**
 * Suggest Tool - Suggest next action to the user
 *
 * This tool allows the agent to suggest a logical next action for the user.
 * The suggestion appears as "ghost text" in the CLI input prompt.
 *
 * Features:
 * - Silent tool (produces no visible output in conversation)
 * - Emits 'suggest' event for CLI to handle
 * - Only the last suggestion per response is kept
 */
import type { Tool } from '../types.js';
import type { AgentEvent } from '../../agent.js';
/**
 * Input parameters for suggest tool
 */
export interface SuggestInput {
    /**
     * The suggested action or command for the user to take next
     */
    action: string;
    /**
     * Brief explanation of why this action is suggested (optional)
     */
    reason?: string;
}
/**
 * Options for creating the suggest tool
 */
export interface SuggestToolOptions {
    /**
     * Callback to emit suggest event
     * The CLI captures this to display the suggestion
     */
    onSuggest?: (event: Extract<AgentEvent, {
        type: 'suggest';
    }>) => void;
}
/**
 * Default suggest tool (no-op, for testing or when suggestions are disabled)
 */
export declare const suggestTool: Tool<SuggestInput>;
/**
 * Create a suggest tool with event emission
 *
 * @example
 * ```typescript
 * const suggestTool = createSuggestTool({
 *   onSuggest: (event) => {
 *     // Handle the suggestion (e.g., pass to CLI input prompt)
 *     console.log('Suggested action:', event.action);
 *   }
 * });
 * agent.registerTool(suggestTool);
 * ```
 */
export declare function createSuggestTool(options?: SuggestToolOptions): Tool<SuggestInput>;