Your company uses Teams. A user named User1 cannot invite guest users to Teams. What should you recommend using to identify the cause of the issue?

The Microsoft Teams Network Assessment Tool measures network quality and connectivity metrics for media, not user permission or guest access configuration issues.

Teams Advisor provides guidance for deploying Teams workloads and assessing organizational readiness, not for diagnosing individual user permission problems.

The Microsoft 365 network connectivity test evaluates network path performance to Microsoft 365 endpoints and does not diagnose guest invitation permissions.

Microsoft 365 self-help diagnostics include a dedicated 'Guest Access in Teams' diagnostic that checks tenant-level, Azure AD, and Teams-specific guest settings to pinpoint exactly why a user cannot invite guests. Running this diagnostic surfaces configuration issues across the multiple layers that control guest access without requiring manual review of each setting. It is the fastest and most targeted tool for this specific scenario.