As a translator , how far do you go in explaining the metaphors during translating an old literature text?

Until I can make sure 100% that the receiver get/will get the meaning of the text. The length is necessary sometimes, but make it as a side note as translation is different than explaining.

Thank you for giving me a chance to answer.

I usually translate (convey) what is behind the lines - explaining metaphors if any. This process is always true, including literature texts.

I explain to where i feel i convey the image that was intended to be delivered.

i have to put the target audience  into my consideration.