Working space where the model can think, calculate and take notes without that appearing in the final answer. It gives the model somewhere to be wrong before it is right, which improves the answer, and it keeps the mess out of the user’s view.
Technical view
Implemented as delimited regions filtered from the displayed output, or as separate reasoning tokens in models that support them. It provides additional computation for a hard problem and allows conditioning on partial results. Note that scratchpad content is not a reliable account of the model’s actual processing, and that it counts fully against context and cost even when discarded.
Related
Part of AI Terminology Index, section: Agents and Tools.