Your agent's memory remembers what you chose. Does it remember what you rejected?

Every memory benchmark I've seen asks the same question: did the right item come back? Recall@k, MRR, hit rate. All measuring whether retrieval surfaces the thing you stored.

That's not the question that costs teams money.

The one that costs money is: you already tried Redis for session caching, it fell over under load, and you ruled it out. Three months later someone asks the agent to "add a caching layer for session data." Does it propose Redis again?

Your memory system stored the choice — "we use Postgres for X." Did it store the veto — "we evaluated Redis and rejected it because of Y"? And if it stored it, does that veto survive long enough to actually stop the re-proposal?

That's what VetoBench measures. It's small, fully reproducible, and — this matters — checked in with every retrieved context, agent reply, and verdict committed to the repo. You don't have to take my word for any number below.