arcgis desktop - Writing Python script tool to enable ModelBuilder to skip over rasters without data?

This modelbuilder works well until the raster to polygon step. At that step, rasters without features cause an error(error 010151). I would like to put in a step before raster to polygon that causes the model to skip over these "feature-less" rasters. I have very little experience with python and rasters and need some help. I tried to make a row count sequence but it didn't work because the rasters did not have a table to check.