I found minor problem. I tried to search for Rakaw/Ракаў/Раков and it find images only for query Rakaw. Images contain descriptions with all variants.
May be tool searches only withing references to page titles?
No, this is another problem, which I have already noted on [[meta:User Talk:Tangotango/Mayflower]]: The tool does not handle non-ascii characters, but instead acts as if they were spaces.