There is little new in terms of demands from the U.S. government that Mexico did not already previously accept. Mexico agreed to deploy its national guard, with focus on its southern border, but such action was already accepted back in March, the only change being a 10% increase in the force to be deployed. Mexico also agreed in December to keep asylum seekers in the country while their cases proceeded in the U.S.
Despite what President Donald Trump says, Mexico did not agree to buy more farm products from the U.S., nor did they accept to become a “safe third country.” Both conditions would have put Mexican finances under stress, as building structures would have forced the delay of other programs.
The agreement is positive for Mexico. The caveat is that it is an open-ended agreement where unspecified metrics have to be met or negotiations will start again. While the major impact has been averted, there is still the issue of further pressure on an already stretched out budget to increase security and provide jobs, health and housing services to migrants. In that scenario, President Lopez Obrador may see his agenda trimmed. Currently, that has little impact on his political standing but could hurt him in the midterm elections when the house and a third of the Senate are renewed.
In short, while this is positive in the short term, there is a fiscal impact to be considered and there is no guarantee the subject will not resurface at any time.