import type { TraceEmitter } from "../observability/request-context.js";
import type { RawToolDefinition, ResolvedToolContext } from "./tool.helpers.js";
export type ToolTimeoutClass = "fast" | "bounded_slow" | "async_candidate" | "interactive";
export type ToolRuntimeErrorCode = "TOOL_TIMEOUT" | "TOOL_CANCELLED" | "TOOL_OUTPUT_TOO_LARGE";
export interface ToolTimeoutPolicy {
    class: ToolTimeoutClass;
    timeoutMs: number;
    maxOutputBytes: number;
}
export interface ToolInvocationRuntimeInput {
    toolName: string;
    tool: Pick<RawToolDefinition, "handler">;
    context: ResolvedToolContext;
    query: unknown;
    signal?: AbortSignal;
    traceEmitter?: TraceEmitter;
    timeoutMs?: number;
    maxOutputBytes?: number;
}
export declare function getToolTimeoutPolicy(toolName: string): ToolTimeoutPolicy;
export declare class ToolRuntimeError extends Error {
    readonly code: ToolRuntimeErrorCode;
    readonly toolName: string;
    readonly policy: ToolTimeoutPolicy;
    constructor(code: ToolRuntimeErrorCode, message: string, toolName: string, policy: ToolTimeoutPolicy);
}
export declare function invokeToolRuntime(input: ToolInvocationRuntimeInput): Promise<string>;
export declare function toolRuntimeErrorToResult(err: unknown): string | null;