As far as the limitations are concerned the AFM is the main reference
I think we do need to be a bit careful here. Usually there is a hierarchy of manuals published that goes something like Notices To Crew, OEBs, OMs, FCOM.. and in case of any conflict you should apply the guidance of the highest in the list. However, taking the most conservative limits shouldn't ever be considered a bad strategy, until that limit is expressly clarified by the operator for which you work.
In the case of a tailwind limitation, such details form part of any initial LCP/OPC so there should never really be any doubt. If there is, then
Citation2 you really need to talk to your new colleagues before operating.