/**
 * [WHO]: validatePlan(), checkPlanStructure()
 * [FROM]: No external dependencies
 * [TO]: Consumed by exit-plan-mode-tool.ts
 * [HERE]: extensions/builtin/plan/plan-validation.ts - plan content validation
 */
/**
 * Validate that a plan has the minimum required structure.
 */
export declare function validatePlan(planContent: string): {
    valid: boolean;
    missingSections: string[];
    suggestions: string[];
};
/**
 * Generate a validation message for the user.
 */
export declare function formatValidationMessage(result: ReturnType<typeof validatePlan>): string;