It seems you are referring to some custom tooltip implementation that is part of the Telerik dashboard demo application -- generally if you are using the built-in tooltip behavior of RadChart (set SeriesDefinition.ShowItemToolTips
property to true), you can also handle the ChartArea.ItemToolTipOpening
event and customize the tooltip contents in the event handler as demonstrated in this online example here
. Note, however, I am not sure whether the RIA service call would do any good in this scenario as in Silverlight it would be asynchronous call and not one blocking the UI.