/**
 * Caller-supplied input failed validation before/while building a provider
 * request: bad request body, malformed tool arguments, unsupported content
 * type, a schema that cannot be normalized, an unknown tool, etc.
 *
 * This is a programmer/config/contract error, not a transient provider fault —
 * it is never retried.
 */
export declare class ValidationError extends Error {
    constructor(message: string, options?: {
        cause?: unknown;
    });
}
/** A referenced tool was not found in the active tool set. */
export declare class ToolNotFoundError extends ValidationError {
    constructor(toolName: string);
}
/**
 * Provider/auth configuration was missing or malformed (env var pointing at a
 * missing file, missing projectId, bad bind string, mTLS half-configured, …).
 */
export declare class ConfigurationError extends Error {
    constructor(message: string, options?: {
        cause?: unknown;
    });
}
/** A request was abandoned because it exceeded a stream/idle/first-event deadline. */
export declare class StreamTimeoutError extends Error {
    constructor(message?: string, options?: {
        cause?: unknown;
    });
}