Claude XML Tags for Prompt Engineering: Complete Reference

<task>
Analyze this quarterly sales data and identify the top 3 trends.
For each trend, explain the cause and recommend one action.
</task>

<context>
We are a B2B SaaS company selling project management software.
Our main competitors are Asana and Monday.com.
We launched a new enterprise tier last quarter.
</context>

<instructions>
- Write in active voice
- Keep each bullet under 20 words
- Do not use jargon
- Output as a numbered list
</instructions>

<examples>
Input: "Our Q3 revenue grew 15%"
Good output: "Revenue surged 15% in Q3, outpacing the 10% industry average."
Bad output: "There was growth in Q3."
</examples>

<role>Senior data analyst with 10 years of experience in retail analytics. You explain findings to non-technical executives.</role>

<task>Should we expand into the UK market?</task>
<thinking>
Consider: market size, competition, regulatory requirements,
currency risk, and our current runway.
</thinking>

<document name="Q4 Report">
[paste your document content here]
</document>
<task>Summarize the key findings from this report in 5 bullets.</task>

<output_format>
## [Section Title]
**Finding:** [one sentence]
**Evidence:** [data point]
**Action:** [recommendation]
</output_format>

<constraints>
- Do not make up statistics
- Do not exceed 500 words
- Do not use passive voice
- If unsure, say "I don't have enough data" rather than guessing
</constraints>

<audience>C-suite executives with no technical background. They have 2 minutes to read this.</audience>

<role>Data analyst</role>
<context>
{{background about your data and business}}
</context>
<task>
Analyze this data and provide actionable insights.
</task>
<document>
{{paste your data here}}
</document>
<output_format>
1. Executive summary (3 sentences)
2. Key metrics table (markdown)
3. Top 3 findings with evidence
4. Recommended actions
</output_format>

<role>Senior software engineer specializing in {{language}}</role>
<task>
Review this code for bugs, performance issues, and security vulnerabilities.
</task>
<document>
{{paste code here}}
</document>
<output_format>
For each issue:
- Severity: critical / warning / info
- Line: location
- Problem: what is wrong
- Fix: code snippet with the correction
</output_format>
<constraints>
- Only flag real issues, not style preferences
- Provide the exact fix, not just a description
</constraints>

<role>{{role, e.g. "B2B SaaS content writer"}}</role>
<context>
{{company info, product details, target audience}}
</context>
<task>
Write a {{content type}} about {{topic}}.
</task>
<examples>
Good headline: "How Stripe Cut Payment Failures by 30%"
Bad headline: "Payment Processing Solutions"
</examples>
<instructions>
- Hook in the first sentence
- One CTA at the end
- Under {{word_count}} words
- Active voice only
</instructions>

<context>
{{describe your situation and constraints}}
</context>
<task>
Evaluate these options and recommend the best path forward.
</task>
<options>
Option A: {{describe}}
Option B: {{describe}}
Option C: {{describe}}
</options>
<thinking>
For each option, analyze:
1. Cost (upfront and ongoing)
2. Timeline to results
3. Risk and mitigation
4. Long-term impact
Then compare and recommend.
</thinking>
<output_format>
| Criteria | Option A | Option B | Option C |
|----------|----------|----------|----------|
| Cost     |          |          |          |
| Timeline |          |          |          |
| Risk     |          |          |          |

Recommendation: [choice] because [reason]
</output_format>

<role>Professional communicator</role>
<context>
{{relationship with recipient, previous interactions}}
</context>
<task>
Draft an email to {{recipient}} about {{subject}}.
</task>
<audience>{{who they are, their priorities}}</audience>
<instructions>
- Under 150 words
- One clear ask
- Friendly but professional tone
</instructions>
<constraints>
- No exclamation marks
- No "just following up" or "per my last email"
- No passive voice
</constraints>

<role>Research analyst</role>
<task>
Synthesize these sources into a briefing document.
</task>
<document name="Source 1">
{{paste source}}
</document>
<document name="Source 2">
{{paste source}}
</document>
<output_format>
1. Executive summary (3 sentences)
2. Key findings (5 bullets)
3. Where sources agree
4. Where sources contradict
5. Gaps in the research
6. Recommended next steps
</output_format>
<constraints>
- Cite which source supports each finding
- Flag any claims without evidence
</constraints>

<context>
Meeting: {{meeting name}}
Attendees: {{who}}
Objective: {{what you want to achieve}}
</context>
<task>
Prepare a meeting brief with agenda, talking points, and anticipated questions.
</task>
<output_format>
## Agenda (30 min)
- [time] [topic]

## Key Talking Points
1. [point] — supporting data: [data]

## Likely Questions & Answers
Q: [question]
A: [prepared response]

## Decision Needed
[what needs to be decided]
</output_format>

<role>Market analyst</role>
<context>
Our product: {{description}}
Our differentiator: {{what makes you unique}}
</context>
<task>
Analyze {{competitor}} and identify opportunities.
</task>
<instructions>
- Focus on actionable gaps, not general observations
- Compare on: pricing, features, positioning, content strategy
- End with 3 specific actions we can take
</instructions>
<output_format>
## Quick Summary
[2 sentences]

## Comparison Table
| Feature | Us | {{competitor}} |
|---------|----|-----------|

## Gaps We Can Exploit
1. [gap] → [action]
</output_format>