For large-scale API testing, which aspect of automation tools is most critical for efficient test execution and reporting?

In large-scale API testing, scalability is crucial as it ensures that the automation tool can handle a large number of test cases efficiently. Scalability enables parallel execution, which speeds up the testing process. It also helps in distributing test execution across multiple machines, ensuring optimal resource utilization. Reporting capabilities are essential for tracking and analyzing test results, providing insights into the overall test health. While script reusability is beneficial, it is not as critical as scalability for large-scale API testing.