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That would be enough to inform future reader who is interested in the tool that it is no longer available.
That would be enough to inform the community to downvote the answer as in current state the answer is wrong
That would be enough to inform the answerer that the link gone broken, and whether they want to fix it or not
The existing wiki answer has great discussion and comments, but I believe the embedded example conflicts with current site standards. The example would be a response to a request for a software list, which would be off-topic (it is a long general description of features and benefits that is not specific to the question and does not provide an actual ...
A quick look at his edits looks like he's just fixing up links and formatting. The quality of these edits at a glance seem... ok, and he's actually taking the effort to write good edit reasons. Seems fine to me!
While there's no official standard formatting, he dosen't seem to be doing that many edits a day, and well, its an improvement.
Initially I ...
Until mid-2010, all links counted toward the limit. This is indeed to prevent spam. Since intra-SE links aren't going to be of much use to spammers (as mentioned by Journeyman Geek in the comments), there was an MSE feature request to exempt them from the accounting. It was approved, implemented (cf. status-completed), and is now in effect.
Some link only answers can be okay if they are specifically telling us what exactly is at the link and showing why it cannot be copied. While we prefer a step by step solution here there isn't really a problem if there is a real reason the answer is a link.
For this reason I would apply the same reasoning and quality requirements we have as I would an answer ...
Any links found in the question, answers or comments will appear in the Linked list on the sidebar. These are manual, by the users.
Those that appear in the Related list are automatically selected by the system.
Should a post like this be flagged for moderator intervention?
No, it shouldn't be flagged just because the link is broken, moderators are already overloaded.
What else you can / should do:
flag it for other reason if you find a valid one - as pointed out already in the previous answer
down-vote - sure, sooner or later there will be enough to move it ...