Covenants which are merely designed to keep an employee from working are not viewed as reasonable by the courts. There must be some way in which the employee's present employment harms the interest of the former employer. A covenant not to compete given by someone selling his or her business to a new owner will be enforced by the courts because the old owner's unavailability is an appropriate way to transfer customer loyalty from the old owner to the new. In many states, if a covenant not to compete is too broad, the courts may have the discretion of reducing the time or geographic coverage to one that is enforceable rather than dismissing the covenant entirely. Because enforcement depends on the discretion of the court, it is nonetheless desirable for the employer to have a suitably limited covenant not to compete to avoid appearing unreasonable.
Courts are, after all, human and often maintain a sense of fairness and a dislike for overreaching.
An overly broad covenant may lead the court to believe it would be inappropriate to enforce the covenant at all. Even when courts are willing to cut down a covenant not to compete to a reasonable time or geographic area, they will not enforce a provision that is unreasonably broad in other regards. Contracts are not one-way streets. They are supposed to be a benefit to both parties. In the normal employment setting, the employer pays wages in return for the employee's services.