Say who it is for and what they will do with it

Ask a model to summarize a 30-page report and you get a summary for nobody in particular. Ask for a summary your finance director will use to decide whether to renew a contract, and you get a different document: the cost first, then the risks, then a recommendation. Same report, same verb. The reader changed the result.

That is the Purpose check: does the prompt say who the result is for and what they will do with it? Leave it out and the model writes for an imaginary average reader with an average need, at medium length, in a neutral tone.

Every writing choice depends on the reader

What to explain, what to skip, what goes first, how formal to be: you make these choices without thinking when you know who will read your work. The model has to make them too, but without a reader it has nothing to go on, so it explains a little of everything.

Summarize this quarter's support tickets.

Summarize this quarter's support tickets for our head of product, who will use the summary to choose the two bugs to fix first next quarter. They will read it on a phone, so keep it under 150 words.

Naming the reader and their decision passes Purpose, and their phone screen sets the length as well.

Notice the second sentence. Once you know the reader, the length and the order follow from it. A summary for a decision leads with the counts that drive the decision, such as how many customers each bug affects, and drops the tickets that were closed in a day.

Say what they will do with it

The second half, the use, often helps more than the reader’s job title. “For my manager” helps a little. “For my manager, who has to approve the spend by Friday” helps a lot: it tells the model to lead with the cost and the recommendation. Anthropic’s guidance makes the same point and suggests giving the reason behind an instruction, such as what the output will be used for.

Lines like these do the job:

• “This goes to new customers who have never used software like ours.”
• “My director reads this on a phone between meetings and has to decide whether to approve the spend.”
• “It’s for the support team, who will paste these replies into tickets.”
• “The readers are engineers who know the system, so skip the basics.”

A reader beats a role

Many prompts open with a role: “You are a world-class communications expert.” A role can set a voice, and it helps in some cases. But it tells the model less than one sentence about who will read the result. If you only have room for one line, spend it on the reader. The name the reader pattern has more examples.

Describe a real person, not a category. “Our finance director, who has not seen this project before” gives the model far more to work with than “a professional audience.”

Explain the changes to our parental leave policy below in plain terms. This is for our employees, most of whom will skim it to see whether the change affects them and what they need to do.

"""
From January 1, paid parental leave increases from 12 weeks to 16 weeks for all employees, including part-time staff. Employees already on leave on January 1 also get the extra 4 weeks. Requests still go through the HR portal at least 30 days before leave starts.
"""

Summarize the attached quarterly website analytics report for our marketing manager, who will use it to decide where next quarter's ad budget goes. Lead with which channels brought in paying customers and which did not.

Rewrite this IT notice in plain words for our warehouse staff, who will read it on the break room screen and need to know what to do and by when.

"""
Effective May 1, all user credentials must be rotated at 90-day intervals and comply with a minimum length requirement of 12 characters. Non-compliant accounts will be suspended pending reset via the self-service portal.
"""

Remember. Say who will read the result and what they will do with it; the right length and order follow from that.