Let's explore how a link-only answer can fall into the flagging spectra:
Let's say I ask a question about, of all things, potatoes. And User X posts a link-only answer (just the link and something in the likes of "your answer is here" or "this page has all the spuds"). Assuming it isn't spam or offensive, there are 3 possible ways to flag.
- Not an Answer
- Very Low Quality
- Other (needs ♦ moderator attention)
Let's start with the Other flag, because it's the easiest to explain and discourage usage. Whenever flagging an answer for Other, we're badgering a diamond-level moderator to come check the answer. Now, moderators are few and busy persons and in no way could they handle every link-only answer that happens to appear on the site. Moderators are there to solve really tricky problems the other flags don't solve (for instance, relevant migration issues).
Now, let's say that the answer actually is a link to a cabbage patch (as such, in no way related to potatoes). I flag it as Not an Answer because, well, it isn't.
Let's say that the answer is a link to a host of resources about potatoes, but it needs work: sufficient expanding and a good explanation. I then flag it as Low Quality, because of the aforementioned faults.
Let's say that the link is to a video that clearly explains the process that would solve my problem, and the amount of work needed to pass over that knowledge to here is minimal. In this case, suggest an edit and add a comment saying how the site should work, if the user is new.
Now, I don't see any inconsistence in the flags, if used as above suggested. Maybe the text in the Very Low Quality flag could be reworded, but consider the following: a link-only answer has a content problem - the link.
Links don't make good answers. Period. Flagging them (either way) does give them a chance to be salvaged, because at least 5 more people will read the answer. If the answer has some sort of merit, one of those 5 people will come and make the appropriate edits. If it has no apparent merit, whenever recommending deletion, there are small comments in place to help the user make a better answer.
- If it doesn't answer the question, flag it as Not an Answer and then delete it (with the optional comment that it is more of a comment than an answer)
- If if does answer the question, but it isn't more than a link with little remarkable content, flag it as Very Low Quality and then educate the user to post a good answer.