While ambiguous_gender does imply a degree of androgyny, androgyny is better understood as similar to femininity or masculinity. You can have unambiguous males that are androgynous and you can have unambiguous females that are androgynous. This is especially the case when taking into account how male and female are defined on this site.
Just like how there's the girly tag for feminine men, it would make sense to have some sort of tag for individuals who are in the center of the masculine-feminine spectrum while still having their penis or pussy out.
Is there such a tag? If not, could there be and how would it best be handled?

if there was a tag it'd probably have to be a split category, androgynous on its own would kind of break the usual format for tags of this nature not to mention it probably being mistagged on ambiguous characters.

if we wanted to do this we'd to add something like androgynous_male and androgynous_female (and I guess androgynous_herm would also be possible). with definitions to the effect of "<gender> characters who, if their <genitals> were not visible/apperent, would be tagged ambiguous_gender"; essentially a stop gap between girly/tomboy and more gender-conformant characters.

I'm not really totally sure how necessary tags like this are, though. I don't think that this is over the line of excessively granularity and we have had at least one recent discussion somewhat adjacent to this subject. but also, like, I'm not 100% on if these tags would be tagged properly or if they'd catch on. it feels like there's a lot of potential for problems with these, and that might outweigh the potential utility.