Attention budget
An informal metaphor for how much supplied information a model can use effectively, not a measurable token allowance.
Illustrative conversation
- The context window still has room, so why remove old logs?
- Capacity is not the same as focus; irrelevant logs spend attention budget that the agent could apply to the current evidence.
Definition
Attention budget is a practical engineering metaphor for a model's finite ability to use the information in its context effectively; it is not a provider-reported meter. As more tokens and possible relationships compete for influence, low-value material can make the important evidence harder to use. Context engineering protects this budget by keeping the smallest high-signal set of instructions, facts, and tool results needed for the next decision.
Reviewed