The purpose of a Trade agreement is to set the rules that nations play by in their economic relationship. These rules can include a number of different things:
Trade agreements often make it possible for companies to sell goods in countries where they would otherwise be barred or overcharged. They may also lower the landed cost of imports. This can be especially helpful in expanding international ecommerce markets.
Other important aspects of trade agreements are commitments to limit protectionism, clarifying how protectionism can be identified in domestic policies, and an enforcement mechanism to help ensure that governments do not violate the spirit of these agreements. In addition, trade agreements can set standards and rules on a wide range of policy issues including intellectual property protection, labor and environmental standards, and foreign investment and regulatory policies.
In general, the vast majority of trade agreements (called free trade agreements or FTAs) are designed to increase commerce between two or more countries by lowering tariff rates and barriers. This is consistent with mainstream economics as understood in this country and around the world. Unfortunately, the Trump Administration has a very different view of the economy and different objectives for its trade negotiations. The result has been long and complicated trade agreements that leave much to be desired.