Background of the issue:
I am working on a site under development and trying to translate taxonomies like tags using WPML.
Symptoms:
When I go to WPML > taxonomy translations > only fields like title, slug and description are available for translation. This means that, to translate the meta description of each tag, I will need to go in wordpress tags (outside of WPML) and work there that require a massive effort if you have many tags and many languages.
I use Yoast to handle metadescription, and I have activated WPML SEO being sure that I could be able to handle everything withing "taxonomy translation". However, as said, in "taxonomy translation" only fields like title, slug and description are available for translation.