/**
 * Fetches the HTML content of a given URL using the browser open command,
 * extracts the text content, and performs validation.
 * @param url The document URL.
 * @param debug Whether to enable debug logging (passed to OpenCommand).
 * @returns A promise that resolves with the extracted text content of the page.
 * @throws If fetching fails after retries or if content validation fails.
 */
export declare function fetchDocContent(url: string, debug: boolean): Promise<string>;