/**
 * Controls whether an eligible Responses API tool can be called directly by
 * the model or from a Programmatic Tool Calling program.
 */
export type ToolAllowedCaller = 'direct' | 'programmatic';
/**
 * A non-empty set of execution contexts allowed to invoke a Responses API
 * tool. Duplicate entries are rejected when tools are created.
 */
export type ToolAllowedCallers = readonly [
    ToolAllowedCaller,
    ...ToolAllowedCaller[]
];
export declare function normalizeToolAllowedCallers(allowedCallers: ToolAllowedCallers | undefined, toolName: string): ToolAllowedCallers | undefined;