As What's the point in adding alt-text to an image? explains, currently, image description text only shows when browsing with images disabled
- and as such, can't be seen at all (and thus is useless) in the vast majority of cases.
- But, it is still inserted automatically into every image added with the toolbar button.
- As a consequence, most leave it as is or delete altogether.
On the other hand (as shown in the same topic), Markdown allows to set the <img>'s title as well which shows as a tooltip when hovering the image -
- pretty helpful.
- However, since this feature is buried in the Markdown docs, few know of this.
- In any case, it requires additional manipulations
- and duplicates the field with the same purpose that's already there.
- (I've read all sorts of SEO papers which describe the nuances between them. Still, I assert that for all purposes of SE posts, they do the same thing.)
So, I'm suggesting to:
Reuse
altastitleunless the latter is specified explicitly.
(Of course, the same can be achieved with JS, but I don't see a need when there's an easy static way. All in all, implementation details aren't that important).
Some references:
- How To Optimize Alt and Title Text on Images - Raven Blog
- Image SEO Optimization - Improve your search rankings
- HTML img tag: title attribute vs. alt attribute?
- Proxomitron has a stock filter for exactly what I'm suggesting
Some previous discussions (apart from what is already linked):
