SELECT name, desired_state_desc, actual_state_desc, reason_desc
FROM sys.database_automatic_tuning_options
When you enabled automatic index tuning for the Performance Recommendations page will identify indexes that can be created or dropped depending on query performance. Remember this feature isn't available for on-premises databases and It is only available for Azure SQL Database.
Creating new indexes can consume resources, and the timing of the index creations is critical to ensure no negative effect is felt on your workloads.
Azure SQL Database will monitor the resources required to implement new indexes to avoid causing performance degradation. The tuning action is postponed until the available resources are available, for example if resources are required for existing workloads and not available for creating an index.
Monitoring ensures any action taken won't harm performance. If an index is dropped and query performance noticeably degrades, the recently dropped index will be automatically recreated