The phrase "be at the disposal of" effectively conveys the idea of being available or ready to use. However, there are several synonyms that can be used to express the same concept. These include "at the ready," "available," "accessible," "reachable," "within reach," "on hand," "at one's beck and call," and "within one's control." Depending on the context, these alternatives may be more suitable for conveying a specific tone or emphasizing a particular aspect of the availability of a resource. By choosing the best synonym for the situation, writers and speakers can create more nuanced and effective communication.