Hi Anthony,
Thank you for your interest in Syncfusion products.
We have a help document for Tooltip.
Please refer the link:
http://help.syncfusion.com/User%20Interface/WPF/GridWith this the sample for the tooltip is attached.
Sample:
http://www.syncfusion.com/uploads/redirect.aspx?file=TooltipSample-95001_dd2c2636.zip&team=developmentRegards,
Jeraldse J