Can a normal chatbot behave like an agent?

It can plan and reason step by step, which is the deciding half of the loop. It cannot act: no search, no file access, no bookings. Asking it to write its plan first and flag steps that need a tool shows you which half of the work your task actually needs.

What is plan-then-execute prompting?

Asking the model to write its numbered plan before doing anything, then to work through the plan in order, showing its reasoning. It makes the steps visible so you can check them, and it usually improves the answer because the model commits to a structure before filling it in.

Why does the prompt say to flag tools it does not have?

Because otherwise a chatbot will narrate actions it never took, such as looking up prices. The flag turns a silent fiction into an honest note, and it tells you which steps would cost a real tool call in an agent.

Try an agent-style task in an ordinary chatbot — Chatbot to Agent

The agent loop is read, decide, act. A plain chatbot cannot act, but it can decide out loud and then work through its own plan. That is most of the value of an agent for many tasks, and it costs one turn instead of twelve. It also shows you, before you buy anything, which steps would have needed a real tool.

The same task, asked two ways.
Prompt	What comes back	What you learn
"Plan a week of dinners for two on $60"	A list of meals, probably over budget, arithmetic unchecked	Nothing about how it got there
"First write PLAN as numbered steps. Then EXECUTE each step, showing your working. Mark any step where you would need a tool you do not have. End with RESULT."	A visible plan, a costed list, a total, and a note that it cannot check today's prices	Which steps are reasoning (free) and which are actions (would cost a tool call)

Try it

Plan first, then execute

Three free runs a day on the site key. Add your own key for unlimited runs.

Now yours

The template below is the same pattern with your task in it. The slot for tools you lack is the important one: a model told it has no calendar will write "you should check the calendar" instead of inventing a free slot on Tuesday.

Your turn

Your own plan-then-execute prompt

What you want doneTools it would normally wantFacts it should use instead

Act like an agent with no tools. First write PLAN: numbered steps to complete the task. Then EXECUTE each step in order using only the information I give you, and under any step that would need a tool ([TOOLS YOU LACK]), say so and use my information instead. Finish with RESULT.

TASK: [TASK]

INFORMATION: [INFORMATION]

Hint: Naming the tools it lacks is what makes it flag actions instead of pretending it did them.

Knowledge check

Your EXECUTE section says "Step 2: I looked up current supermarket prices and found chicken at $8.50/kg." You gave it a price list with chicken at $9. What happened?

Try an agent-style task in an ordinary chatbot

Now yours

Lesson FAQ

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