You get a list of databases with their sizes, and at the top level you get a list of server-wide reports:

Generate reports about current activity, for example:

You can also build charts on IO and other metrics. They are based on performance_schema cumulative counters, interpreted as deltas during a 30 seconds interval:

You can filter the error log by day:

You can inspect the contents of MySQL functions and procedures to check that correct version is installed:

And finally, for the tables you can get sizes, fragmentation and selectivity per date (without having access to the fact data, which can be sensitive):

The index coverage report lists all columns, covered by any index at least once. Leading column in an index is marked with '1', second with '2' etc. You can easily spot overindexing and bad indexing.