watershed description may be erroneous

The watershed package's description currently reads:

watershed may be run around a command such that any further attempts to run the command while another copy is running will only result in one initial further attempt.

It is hard to tell what watershed is actually trying to do (there is no README in the package, and the code itself dives right into technicalities without establishing context or intent), but I suspect it is not what the description is stating. I assume that watershed's intent is to prevent more than one instance of a command from running at any given time. What the description states is that multiple watershed-wrapped command instances will result in *two* running instances: the first running copy, and the "one initial further attempt".

Either way, this needs clarification.