An agent fleet wired to a high-volume trigger source — channel mentions, queue events, webhooks — pays full cost on every cycle, even when the trigger is noise. A classifier placed in front of the main agent decides which triggers deserve a real cycle and which to drop. The pattern is old; what is new is that local LLMs make the classifier cost effectively zero, which flips the arithmetic in the pattern’s favor for cases that previously didn’t justify the latency.