The icon means that the specific agent has exceeded the per-agent metric clamp value, which is set in the <EM_Home>\config\apm-events-thresholds-config.xml:
APM Clamps and Important Events configuration file. Please refer apm-evets-thresholds-config.xsd for schema file.
This configuration configures the pre-defined the clamps and important events. Each clamp/important event
threshold value will be applied for each agent or entire EM depends configuration.
Most properties here put limits on # of metrics.
The last limits metric data. The metric clamping properties support hot config.
Per Agent limit. Takes into account live and historical metrics.
You can also click on the mushroom-like red icon on the top right corner of the Workstation Investigator, which will open up the APM Status Console. In this window, you will see what is the threshold set for this agent, and what is the current count of the metrics it is reporting. Clicking on the record will redirect to the Historical Metric Count metric for this agent at the following path:
SuperDomain*|Custom Metric Host (Virtual)|Custom Metric Process (Virtual)|Custom Metric Agent (Virtual)|Agents|<host>|<Process>|<Agent>: Historical Metric Count