write-email · claude-3-5-sonnet · communication · 90% confidence

Write an email with Claude 3.5 Sonnet — optimized prompt

A Claude 3.5 Sonnet email prompt with <context>, <goal>, <must_include> and <tone> tags, plus a one-line callout of the sentence most likely to be misread.

90% confidenceUpdated 9/7/2026write-email · claude-3-5-sonnet · communication

Original prompt

Hey Claude, help me write an email to a client explaining that the project is delayed. Be professional.

Optimized prompt

Draft one email. Diplomatic phrasing matters here — the reader is likely to be annoyed.

<context>
[who the reader is, the relationship, relevant history]
</context>

<goal>
[the single outcome you want from this email]
</goal>

<must_include>
- [fact / commitment]
- [fact / commitment]
</must_include>

<tone>[e.g. "accountable, not grovelling; specific about next steps"]</tone>

<constraints>[length, anything to avoid]</constraints>

Output:
1. Subject line + body.
2. One line: which sentence is most likely to be misread, and the safer alternative.
Mark any missing fact as [NEEDS: ...] rather than inventing it.

Why this Claude 3.5 Sonnet prompt works

Tuned for Claude 3.5 Sonnet: <context>, <goal>, <must_include> and <tone> tags, plus a callout of the one sentence most likely to be misread. Claude is strong at diplomatic phrasing and the misread-check catches the line that would land wrong.

What to check in the output

The optimized prompt explicitly defines the AI's persona and task.
The optimized prompt provides distinct categories for key information to be included.
The optimized prompt includes a step-by-step 'Chain of Thought' for generating the email content.