/**
 * Invoke a single MCP server tool (capability).
 *
 * This is the durable activity that wraps `callServerTool`.
 * Running as a proxied activity gives crash safety — if the
 * container dies mid-call, HotMesh retries on another container.
 */
export declare function callCapability(input: {
    serverId: string;
    toolName: string;
    arguments: Record<string, any>;
}): Promise<any>;