Each tool has a clearly distinct purpose with no ambiguity. create_payment_preference handles payment initiation, create_refund manages refunds, get_merchant_info retrieves merchant data, get_payment fetches specific payment details, and search_payments searches multiple payments. The descriptions clearly differentiate their functions, making misselection unlikely.

All tool names follow a consistent verb_noun pattern using snake_case. The verbs (create, get, search) are applied logically to their respective nouns (payment_preference, refund, merchant_info, payment, payments), creating a predictable and readable naming convention throughout the set.

With 5 tools, the server is well-scoped for payment processing with Mercado Pago. Each tool earns its place by covering core operations: payment creation, refunds, merchant information retrieval, payment lookup, and payment searching. This count is neither too sparse nor bloated for the domain.

The tool set provides strong coverage for key payment workflows, including creation, retrieval, searching, and refunds. A minor gap exists in the lack of update or cancellation tools for payments or preferences, but agents can likely work around this given the available operations cover most essential tasks.