Thank you for your question.
There is no way to specify the width or height of the tooltip. However, you can modify its displaying location and also limit the length of its text on the ToolTipTextNeeded
event as it is shown in the following code snippet:
sender, Telerik.WinControls.ToolTipTextNeededEventArgs e)
//Specifies the offset according to the current position of the mouse cursor
Size(e.Offset.Width + 20, e.Offset.Height + 20);
//Specifies the text that will be displayed in the tooltip
e.ToolTipText = e.ToolTipText.Substring(0, Math.Min(75,e.ToolTipText.Length));
I hope you find this helpful. If you have any additional questions, do not hesitate to write back.
the Telerik team