Three lines, three roles
Write a system line that sets the job.
Write a user line that asks one question.
Write a tool line that returns a number you computed outside the model.
The reply may quote the tool line and must not invent a second number.
Sources and go deeper
- Anthropic, Building effective agents vendor last checked 2026-10
- Amazon Bedrock overview vendor last checked 2026-10
- Prompt engineering — Wikipedia wikipedia last checked 2026-10