/**
 * Tool-result serialization shared by Anthropic's client and its loop adapter.
 *
 * Extracted rather than exported from `client.ts` because the adapter is
 * imported BY the client: importing back the other way would close a cycle.
 * The behaviour is unchanged from the module-private version it replaces.
 */
/** Serialize a tool-result `output` into text for a tool_result block. */
export declare const stringifyAnthropicToolOutput: (output: unknown) => string;