How to build an adversarial eval for your agent cache (and why 18 pairs matter more than a benchmark)
Benchmarks tell you how often a cache helps. They don't tell you when it hurts. For an agent cache, the dangerous question isn't "how many hits did you get?" — it's "did you ever serve the wrong trajectory?" One wrong replay of a write step — deactivate instead of activate, refund instead of charge — costs more than a thousand saved tokens are worth. So before trusting any cache on agent traffic, build it an enemy test: pairs of requests that are semantically close but must never be confused. T…