You can set up inline field documentation for your reports using the Field Documentation functionality of Easy Insight. For tabular reports, you can set each column to have a hover option, while for non-tabular reports, you can add an overall report hover to explain the different fields in the report.
You can add documentation for a field by editing the field in the report and putting a value in the 'Tooltip' section, or you can set documentation at the data source level to apply across all reports. You can configure documentation by going to Configuration on the data source page, then clicking on Field Documentation:
You can use the dropdown to filter the view to only show fields for a certain folder:
If you haven't configured any documentation of your own, any default field documentation available for the connection in Easy Insight will automatically come across as well.
Once configured, the inline help will automatically show for the column headers of tabular reports like lists or trees:
You can enable a report level display of the documentation for charts, maps, and other report types by doing Configuration -> Report Properties -> Formatting and toggling the 'Show Field Documentation' setting to on:
Once enabled, you'll see a help icon next to the report name in dashboard or report views that users can hover over to pull up the field documentation: