When is it safe for an AI agent to act autonomously? The confidence gate
Autonomous agents are only useful if they can act without asking a human every time — but acting on a wrong diagnosis is worse than not acting at all. The resolution isn't "trust the model more." It's a gate: a machine-readable rule for exactly when it's safe to act, and when to escalate.
The three factors
All three must be true to auto-act. Miss any one and the agent escalates. This is deliberately conservative — it fails closed.
Why 'source' is the unlock
The most dangerous failure mode is a confidently wrong answer — an LLM inference that sounds right and isn't. If your agent can't tell a verified library fix from an LLM guess, it can't safely auto-act on either. Surfacing source: "library" vs "llm" in the response is what makes the gate possible: auto-act on the verified answer, escalate the guess.
The gate in one line: auto_apply_ok = (confidence >= 0.85) AND (source == "library") AND auto_safe. Snapback returns all four fields on every diagnosis, plus a ready-made gate.auto_apply_ok — so the agent doesn't have to derive the rule, just read it.
What auto-acts vs what escalates
- Auto-act (reversible): retry a deadlock with backoff, re-fetch a stale offer and re-price, serve the intermediate cert, raise max_tokens on a truncation.
- Escalate (irreversible / state-changing): create an on-chain account, allow-list a blocked card, obtain a new OAuth mandate, anything that deletes or reverts.
This mapping is the difference between an agent you can trust to run unattended and one you can't. Get the gate right and autonomy stops being scary.
Machine-readable guide: https://snapback.sh/llms.txt · Tool discovery: https://snapback.sh/.well-known/mcp.json · MCP endpoint: https://api.snapback.sh/mcp. Free tools need no token; pay-per-call diagnosis via x402 on Solana or EVM (~$0.0032 USDC).