Your agent just fired 1,200 requests in ninety seconds. MCP Hangar's dual rate limiting — token bucket on the command bus, exponential backoff on auth — puts a ceiling on runaway tool calls.
Your LLM just deleted a production alert rule. The approval gate blocks irreversible operations — not every call, just the ones where 'undo' means filing a support ticket.
5,300 measurements, 6 scenarios. The headline is 19.6× speedup — the real findings are that stdio isn't serial, framework overhead is zero, and a hardcoded constant was capping your throughput.