export interface DeclaredOutputField {
    name: string;
    type: string;
    required: boolean;
    constraint: string;
}
/** Validates a result object against declared output field descriptors.
 *  Returns null if valid; otherwise returns a { field, receivedType } error. */
export declare function validateDeclaredResult(output: DeclaredOutputField[], result: Record<string, unknown>): {
    field: string;
    receivedType?: string;
} | null;
/** Core leaf declarations may explicitly require a nullable field. */
export declare function validateCoreDeclaredResult(output: DeclaredOutputField[], result: Record<string, unknown>): {
    field: string;
    receivedType?: string;
} | null;