Knowledge card L1 · Basic prompts informational

Start by Telling Claude Who It Is and Who You Are

What it is

A reliable first-message shape for Claude: name the role you want it to take, give the context you're working in, state the constraints, then make the ask — in that order.

a first message that worksRolewho Claude should be4Contextwhat you're doing3Constraintsformat, length, must-nots2The askwhat you want1
Four lines that turn a cold start into a useful one.

Why it works

Claude has no memory of you at the start of a chat. The first message is the entire world it reasons from. A little structure up front replaces a dozen clarifying round-trips later.

When to use it

The opening message of any non-trivial task. The higher the stakes or the more specific the output, the more the framing pays off.

When not to use it

Quick factual questions or casual chat — there the ceremony is slower than just asking.

Prompt

You are <role, e.g. a senior back-end engineer>.
Context: <what I'm building and why>.
Constraints: <language, style, length, what to avoid>.

Task: <the specific ask>.

Example

Opening with 'You are a copy editor for a fintech blog; keep it plain and non-hyped; tighten this paragraph' gets a focused edit instead of a generic rewrite that adds buzzwords.

Advanced version

For work you repeat, save your best framing and reuse it. When you find yourself pasting the same setup often, graduate it into a Claude Project so the context is always on.

Common mistakes

  • Opening with the bare task and then spending five messages adding the context you could have led with.
  • Assigning a role but no constraints, so tone and length are a coin flip.
  • Writing a paragraph of role-play backstory that adds flavour but no signal.

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