Concise and descriptive... good!
... precise and complete: also required, or, at least, a very good idea!

The original post -- read very carefully -- arguably satisfies all of those or comes close (but the fact that you don't care what any differences are comes out only later). Nonetheless, a couple extra words would make the spec a lot clearer: for example,

s/The script will make a text file "foo.txt" and then query every other host in the system to see if the contents of "foo.txt" agree./A copy of the script on each host will make a text file...if the content of that host's "foo.txt" agrees with the local copy./

(And, BTW, what are your criteria for "agree?" If some of your hosts are *n*x and some 'doze, are variant line endings allowed? What about the timestamps?)

Further, as some nodes in this thread make clear: those who would help would like to know what the triggering event is; whether you have a plan for having each of N hosts check with each of the others, and perhaps even 'how you intend to use a report of differences' since that might restrict (or broaden) your options.