Which task must a MID perform in a cluster according to its defined capabilities?

The task that a MID (Management, Instrumentation, and Discovery) server must perform in a cluster according to its defined capabilities is to check the ECC Queue for either processing or ready jobs. This process is vital for managing and distributing workloads effectively across the cluster. The ECC Queue acts as a communication channel between various components of the ServiceNow platform and the MID Server, ensuring that any jobs requiring execution are managed efficiently.

By monitoring the ECC Queue, the MID Server can identify jobs queued for processing, which may include tasks like discovery, data import, or integration tasks. This enables the MID Server to initiate the processing of these tasks based on the current load and defined parameters, ensuring timely and effective execution. This responsibility is crucial in maintaining the overall performance and operational efficiency of the Discovery process within the ServiceNow ecosystem.

In contrast, the other options touch on scenarios that do not accurately reflect the primary operational responsibilities of a MID Server in a cluster. For instance, processing data only from known devices and limiting workload based on network capacity provides operational guidance but does not articulate the fundamental role of job management via the ECC Queue. Thus, monitoring this queue is a core function that aligns directly with a MID Server's capabilities and its role in cluster operations.