Microsoft Support Diagnostic Tool (MSDT) interactive communication with Microsoft must be prevented.
Some features may communicate with the vendor, sending system information or downloading data or components for the feature. Turning off this capability will prevent potentially sensitive information from being sent outside the enterprise and uncontrolled updates to the system.
This setting prevents the MSDT from communicating with and sending collected data to Microsoft, the default support provider.
How this relates to the STIG checklist: STIG vs SCAP benchmark.