I'm getting to disagree with the current use of this tag, so I thought of bringing it up here to see what opinions there are on it. Frankly I would prefer androgynous to be completely "tag what you see" in usage. I don't think it should apply simply because a character canonically doesn't have a gender or it's unknown. I've found androgynous to be quite useful, for instance, in identifying depictions of effeminate otoko no ko characters that are a bit more masculine than usual. The intersection of those usages causes problematic dilution in cases like Fate/Grand Order. Should it really be "androgynous" for something like post #2777709 when they both look very girly? The tag is also getting filled up lately with the gems from Houseki no Kuni who are genderless but also including instances where they don't really look particularly androgynous like post #2946774. The ambiguous gender tag exists, but it also has a bit of "tag what you see" element to it in that it's often been used when people are too indistinct (covered in armor, too far out of view, etc.) to make out a gender. Whether it should overlap with people who are of canonically ambiguous gender is another question, but I do think it would be less problematic than using androgynous for that purpose. It's not technically true for Houseki no Kuni, but maybe we could create a tag like genderless or no gender?
And it's come up in other discussions too, but I also really think (particularly with Houseki no Kuni being unsearchable compared to other franchises in this regard) that there should be counters for humanoids of unidentified or no gender. I feel like 1person, 2people, 3people, etc. would be the least awkward-sounding solution but also unintuitive in that it might look applicable to characters of known gender.