After years of debate and dialogue at the international level, it’s possible that Sustainable Development Goal (SDG)-fatigue will lead to settling for practical, achievable goals and targets over ambitious principles that strengthen norms and give national groups a further point of leverage. Exhaustion from international processes, and short deadlines for national targets, could truncate the needed dialogue at the national level in favour of a technocratic process to determine national targets. Drawing evidence from over 150 pieces of literature on international agreements, this paper proposes lessons for the design of the SDGs. They key message is that we should not let practicality blunt our ambition, but instead take time to make sure that global goals can be used for real problem solving around the world. It suggests we may need to look at the SDGs as closer analogues to international human rights and environmental agreements than international programmes or, even, than their predecessors, the Millennium Development Goals.