r/AI_Agents: Production Builders Warn Agent Failures Are Almost Never the Model — Missing Stop Button, Audit Trail, and Spend Cap Are the Real Gaps

A production builder argues from extensive deployment experience that model quality is rarely the real failure point in agent systems — the actual gaps are infrastructure: no circuit breaker to halt runaway loops, no per-session spend cap on tool calls, no structured audit trail to reconstruct agent decision chains, and no rollback path when an action causes downstream harm. The post catalogs four recurring failure modes that account for most production incidents, framing them as engineering problems that model upgrades cannot fix. Community responses confirm similar patterns with specific examples of tool calls escalating uncontrolled, API bills spiking overnight, and agents acting on stale context with no observability into what happened.