export declare class Ga4AuthError extends Error {
    readonly cause?: unknown | undefined;
    constructor(message: string, cause?: unknown | undefined);
}
export declare class Ga4RateLimitError extends Error {
    readonly retryAfterMs: number;
    constructor(retryAfterMs: number, cause?: unknown);
}
export declare class Ga4ServiceError extends Error {
    readonly cause?: unknown | undefined;
    constructor(message: string, cause?: unknown | undefined);
}
/**
 * Thrown when a required tool argument is missing, the wrong type, or carries
 * a sentinel "undefined"/"null" string. Surfaced as a structured error envelope
 * so callers see "InvalidArgumentError" + which arg failed, instead of the
 * server hanging on a downstream API call with a malformed property_id.
 */
export declare class Ga4InvalidArgumentError extends Error {
    readonly argName: string;
    readonly reason: string;
    constructor(argName: string, reason: string);
}
/**
 * Validate that a tool argument is a non-empty string and not the literal
 * "undefined" / "null" sentinels that LLM clients sometimes send.
 * Throws Ga4InvalidArgumentError, caught by the dispatch envelope.
 */
export declare function requireStringArg(name: string, value: unknown): string;
export declare function validateCredentials(): {
    valid: boolean;
    missing: string[];
};
export declare function classifyError(error: any): Error;