Think Before You Touch

The principle

Asking a model to reason step by step before answering measurably improves results, and for an agent the stakes are lopsided. A reasoning trace is cheap and easy to undo. An executed action, a sent email, a dropped table, a charged card, is not. Letting the model lay out its plan in tokens before it commits is the cheapest insurance you can buy.

Why it happens

A plan is cheap and reversible. A tool call may not be. Asking the model to state the target, scope, and expected effect before acting gives you a low-cost checkpoint before the expensive step. ReAct showed that interleaving reasoning and action helps agents track state and recover from surprises, but the broader rule is simpler: spend disposable tokens before irreversible actions. If the plan is wrong, discard it. If the email is sent, the table is dropped, or the card is charged, the cost is real.

Watch for

• The agent fires a side-effecting tool call with no stated plan or scope beforehand.
• Destructive actions execute on the first instinct, then turn out to have hit the wrong target.
• Post-mortems show the agent never articulated what it was about to do or why.

Apply it

1. Require an explicit reasoning or plan step before any tool call that has side effects.
2. Make the plan state the exact target, scope, and expected effect (for example the row count) before acting.
3. Treat reasoning tokens as cheap insurance and spend them freely ahead of any irreversible action.

Sources and further reading

• Chain-of-Thought Prompting Elicits Reasoning in LLMs · Wei et al., 2022
• ReAct: Synergizing Reasoning and Acting in Language Models · Yao et al., 2022