It allowed the US government to work with other countries to reduce tariffs.
The Smoot-Hawley tariff, passed in June 1930, raised import tariffs to unprecedented levels, which virtually closed the US borders to foreign products. Thus, this tariff closed the US economy to the rest of the world and caused similar reactions, which would hinder US exports.
In the context of the economic depression, the situation of the world economy was bad, so that international trade was seen by Roosevelt as a way to stimulate the world economy, inducing production, commerce and consequently increasing employment and income. Thus, a policy of reciprocal trade agreements would encourage countries to adopt free trade measures, since they would have access to the US market.