Two of his years of contract control are gone.
If he follows the trend of other Star Players, he'll want a new contract next year.
Considering the size of the Landon Collins contract, the loss of two years from the Adams contract is very significant.
On the plus side, he is an immediate contributor at the position the Cowboys need long term (Strong Safety).
Adams at SS would give the Cowboys the option of Heath at FS while X.Woods is out.
I don't know why the Jets would want to trade away players. They just signed Le'veon Bell to a big contract. They don't appear to be in (intentional) tank mode.