When the chart's width is constrained it does not scale to fit and the labels get cut off. I found this post but do not see any of these settings in the Html/Javascript version of the pie chart
http://www.telerik.com/forums/pie-chart-labels-are-being-cut-off
Changing the margins/paddings is not an ideal solution as we have dynamic data populating the pie charts so one setting that may work might not work for another dataset.