When a prompt mixes instructions, pasted text and examples, the model has to work out where each part starts. A little structure removes the guesswork, and it is also a safety habit: it keeps pasted text from reading like more instructions.

Mark off the text to work on

OpenAI recommends putting the instructions first and separating them from the context with ### or triple quotes. The model can then tell what is a request and what is material.

Summarise the text below as 5 bullet points.

Text: """
{{text}}
"""

Use XML tags for Claude

Anthropic suggests wrapping each kind of content in its own tag when a prompt mixes instructions, context, examples and variable input. Use clear, consistent names and nest them when the content has a hierarchy.

<instructions>Summarise the report for a board meeting.</instructions>
<context>The board decides on the budget on Friday.</context>
<report>{{report}}</report>

Promptor writes prompts with tags when you choose Claude, and with headings for the other choices.

Put very long documents first

This is where the guides differ. For short prompts, instructions first reads well. For a very long document, Anthropic finds that putting the document above your question, and ending with the question, improves the answer. If you work with long inputs and Claude, follow that; otherwise keep instructions first.

Write steps as a numbered list

If order matters, or every step must happen, number them. Anthropic recommends sequential steps for this. A sentence that says “read the report, then list the risks, then rank them, and finally write a summary” is easier to skip a step in than a list.

1. Read the report.
2. List the risks, one per line.
3. Rank them from most to least serious.
4. Write a summary of 5 bullet points.

Keep each prompt to one job

A very long prompt asks for many things at once. Atlassian describes prompt chaining: use the answer to one prompt as the input to the next. Anthropic also lists chaining complex prompts among its tips for agentic systems. Smaller prompts are easier to check and to fix.

What to try

  • Wrap pasted text in triple quotes, a tag or a heading.
  • Number steps that must happen in order.
  • Split a long prompt in two when the first answer would help the second.
  • Run the result through Promptor to see what it still flags.