Cmdstan's diagnose utility - better error checking / error messages?

what checks should the cmdstan diagnose utility impose on a set of inputs?

I ran it on a set of files, carelessly specified as *.csv, not realizing that there was one file from a different run hanging around - this was the last file to be read in. it had a different value for max_depth than the others. the stats reported made no sense.

which metadata values need to be the same across input files in order to this utility to work correctly?