list the minimum scale values for all layers in an mxd (the don't show out-beyond scale)

list_min_scales.py

#################################################################################
#
# Requirements: You'll need ArcGIS Desktop 10.1 or higher with Python 2.7 
#
# If you are publishing an MXD as a map service you might get a warning from
# the Analyze option that some number of layers "draws at all scale ranges".
#
# This script lists all the layers in the MXD you have open and what their 
# minimum scale is set at, if at all. Those with '0.0' values have no value set.
#
# Instructions: This is code you can copy/paste into the ArcMap Python 
# interactive console with the MXD open that you wish to review.
#
# You can copy/paste it all at once, or you can paste a little bit at a time to 
# modify what ever needs changing.
#
# Feel free to use, rewrite, and distribute as you wish.
# As always, use at your own risk!
#
#################################################################################

# set your mxd and get list of layers
mxd = arcpy.mapping.MapDocument("CURRENT")
lyrs = arcpy.mapping.ListLayers(mxd)

# output a list of layer: scale pairs to the console
for lyr in lyrs:
    print lyr.name + ": " + str(lyr.minScale)