This issue comes and goes. Currently the tools appear to be working fine. We once believed it was related to the replication database, but evidence has since suggested otherwise. Sometimes the edit counter will have zero results but the article-info tool will work as expected. Cyberpower678/Technical 13/PHP people, perhaps dive into the code and put a check in to see if zero results are returned, and if there are, have it print out to the logs as much relevant information as possible. That's my best suggestion as the issue is sporadic and the logging we already have doesn't seem to offer many clues.
I'll happily troubleshoot this specific situation once we are moved into our own xtools.wmflabs.org instance. I'll have it email me everything when 0 results happen until I can find the cause.