Few-shot prompting with Claude XML

How to use / tags to demonstrate the task before the live input.

How to apply the pattern

1. Define the task in <instructions>. Be explicit about the output format — even one sentence.
2. Pick 2–5 representative examples. Cover the real distribution: edge cases included, not all the happy path.
3. Wrap each example with <input> and <output>. Or task-specific equivalents like <q>/<a>.
4. Put the live input after the examples. Order matters — Claude treats what comes last as the active query.

Worked example

<instructions>
Extract the company name from each press release headline.
Return only the company name, no other text.
</instructions>

<examples>
  <example>
    <input>Acme Corp announces Q3 earnings beat</input>
    <output>Acme Corp</output>
  </example>
  <example>
    <input>Globex shutters European division</input>
    <output>Globex</output>
  </example>
  <example>
    <input>Sources: Initech in talks to acquire Pied Piper</input>
    <output>Initech</output>
  </example>
</examples>

<headline>{{ live_headline }}</headline>

Tips

• If accuracy doesn't improve with examples, you probably don't need them — Claude is strong zero-shot.
• Don't include examples from your real production data unless you've handled PII.
• More than ~5 examples rarely helps and bloats your context budget.