Summarise for a Specific Reader and Purpose

Telling Claude who the summary is for and what they'll do with it — 'for an executive deciding whether to fund this', 'for an engineer who needs the technical constraints' — so the summary keeps what that reader needs and cuts what they don't, rather than producing a generic shrink of the source.

A summary is a choice about what to keep, and that choice only has a right answer once you know the reader and the purpose. Without them, Claude defaults to preserving what the author emphasised — which may be exactly the wrong material for your reader. Name the audience and their goal and the same source yields a genuinely different, more useful summary: the executive version leads with cost and recommendation; the engineer version leads with constraints and dependencies. Purpose turns 'shorter' into 'relevant', which is the whole point of summarising.

Any summary with a known destination and reader: a brief for your boss, notes for a teammate, a digest you'll act on yourself. Especially when the source was written for a different audience than the one you're serving.

When you genuinely just need a neutral gist to orient yourself before deciding what matters — a first-pass 'what is this about' doesn't need targeting. Add the reader and purpose once you know how the summary will be used.

Summarise this for a specific reader and purpose.
Reader: <who they are and what they already know>.
Purpose: <the decision they'll make or action they'll take>.

Keep only what serves that, lead with what they need first, and cut detail that doesn't change their decision. Source: <paste or attach>.

You feed Claude a dense technical postmortem. 'Summarise for the leadership team deciding whether to delay the launch' produces a tight brief leading with impact, risk, and a recommendation. 'Summarise for the engineers who'll fix it' produces a different summary leading with root cause and the specific systems to change. Same document, two summaries, each usable by its reader without further work.

For a source that serves multiple audiences, ask for a layered output: a two-line version for the decision-maker on top, then a deeper section for the doer beneath. Each reader stops where their need is met, and you've produced one artefact that serves the whole chain instead of writing three separate summaries.

• Asking to 'summarise' with no reader or purpose, then reworking the generic result into what you actually needed.
• Preserving the source's own emphasis when your reader cares about something the author barely mentioned.
• Naming the audience but not what they'll do — 'for executives' is vague; 'for executives deciding X' is actionable.