Why is ArcPy Describe Extent overshooting the extents?

Question

Why is arcpy.Describe(file.shp).extent overshooting the extent? Screenshot below. I have confirmed there are no tiny lines lingering out at the edges. I'm in UTM coordinates.

extent = arcpy.Describe(Lines.shp).extent
xmin = extent.XMin
xmax = extent.XMax
ymin = extent.YMin
ymax = extent.YMax

print xmin, xmax, ymin, ymax

Print output:

540375.245005 546724.102422 3814174.9483 3818495.05067

EDIT: I tried adding in a minimum bounding geometry, still same issue.

test_out = outpath + '\\' + 'temp_convexHull.shp'
arcpy.MinimumBoundingGeometry_management(Lines.shp, test_out, "CONVEX_HULL", "ALL", "", "")

extent = arcpy.Describe(test_out).extent
xmin = extent.XMin
xmax = extent.XMax
ymin = extent.YMin
ymax = extent.YMax

print xmin, xmax, ymin, ymax

Answer 1

Your thinking is slightly wrong

xmin = extent.XMin
xmax = extent.XMax
ymin = extent.YMin
ymax = extent.YMax

gives you this and it is OK and what envelope means.