I reproduce only a horizontal scrollbar showing briefly if a too long value is displayed in the Tooltip at the rightmost part of the Chart and page. However, this scrollbar is quickly hidden as the tooltip is automatically re-positioned according to its size.
If you want to control the tooltip position with your own logic, you can handle the Chart seriesHover event and show a tooltip of your own. A similar example is available here: Show Tooltip on seriesClick
You just need to replace seriesClick with seriesHover and adjust the tooltip positioning logic.
Additionally, please note that these are the forums of the AppBuilder IDE for mobile apps development. If you have additional questions about the Chart, please post them in the Kendo UI forums or in a Kendo UI support ticket.