You can add a ToolTip to each data point on the series of a chart to display information related to the data point, such as the group name, the value of the data point, or the percentage of the data point relative to the series total. When users hover over the data point in a rendered paginated report, they'll see this information.
You cannot add a ToolTip to a calculated series.
You can create and modify paginated report definition (.rdl) files in Report Builder and in Report Designer in SQL Server Data Tools. Each authoring environment provides different ways to create, open, and save reports and related items.
To specify a ToolTip on each data point
Right-click on the series or right-click on the field in the Values area, and click Series Properties.
Click Series Data and, for the ToolTip property, type in a string or expression. You can use any chart-specific keyword to represent another element on the chart. For more information, see Formatting Data Points on a Chart (Report Builder and SSRS).
Formatting Data Points on a Chart (Report Builder and SSRS)
Change the Text of a Legend Item (Report Builder and SSRS)
Formatting Series Colors on a Chart (Report Builder and SSRS)
Add a Drillthrough Action on a Report (Report Builder and SSRS)