Claude Prompt Guide

SKILL: Claude Prompt Guide

Purpose: Document Anthropic XML tag patterns and prompt engineering best practices Target: All agents creating or modifying system prompts, commands, and skills

Quick Start

When to Use This Skill

• Creating new system prompts or agent instructions
• Modifying existing command or skill behavior
• Debugging prompt-related issues

Quick Reference

<do_not_act_before_instructions>Defer action until conditions met</do_not_act_before_instructions>
<default_to_action>Prefer tool use over chat responses</default_to_action>
<use_parallel_tool_calls>Execute independent tools simultaneously</use_parallel_tool_calls>
<investigate_before_answering>Research before responding</investigate_before_answering>
<avoid_excessive_markdown_and_bullet_points>Prefer prose over lists</avoid_excessive_markdown_and_bullet_points>

What This Skill Covers

In Scope

• Anthropic official behavior control XML patterns
• System prompt internal tag structure
• 10-Component Framework for effective prompts
• Best practices (DO/DON'T)

Out of Scope

• Model-specific tuning → @.claude/skills/coding-standards/SKILL.md
• Agent role definitions → @.claude/agents/CONTEXT.md

Core Concepts

CRITICAL: Tag Names Are Customizable

XML tag names are NOT magic - the content/instructions matter, not the tag name.

Official Behavior Control Tags

<do_not_act_before_instructions> - Control When to Defer Action

Purpose: Prevent premature tool use or implementation When to Use: Read-only phases, planning stages

<do_not_act_before_instructions>
This is a READ-ONLY planning phase. Do not use Edit tool or modify any files.
Only proceed with implementation when the user explicitly runs `/01_confirm` → `/02_execute`.
</do_not_act_before_instructions>

<default_to_action> - Encourage Proactive Tool Use

Purpose: Prefer tool execution over chat-only responses

<default_to_action>
Prefer taking action through tool use rather than providing lengthy explanations.
</default_to_action>

<use_parallel_tool_calls> - Optimize for Parallel Execution

Purpose: Execute independent operations simultaneously

<use_parallel_tool_calls>
Execute independent operations in parallel using separate tool calls.
</use_parallel_tool_calls>

<investigate_before_answering> - Research Before Responding

Purpose: Ensure thorough context gathering before response generation

<investigate_before_answering>
Before providing recommendations, thoroughly investigate the codebase:
1. Read relevant source files
2. Search for related patterns
3. Check existing tests and documentation
</investigate_before_answering>

<avoid_excessive_markdown_and_bullet_points> - Control Output Format

Purpose: Prefer concise prose over structured lists

<avoid_excessive_markdown_and_bullet_points>
Prefer natural language prose over excessive bullet points and markdown formatting.
</avoid_excessive_markdown_and_bullet_points>

System Prompt Internal Tags

<!-- Behavior control -->
<behavior_instructions>Core behavioral guidelines</behavior_instructions>
<system-reminder>Context injection during conversation</system-reminder>

<!-- Tool use control -->
<tool_use_instructions>Guidelines for tool invocation</tool_use_instructions>

<!-- Context injection -->
<claudeMd>Codebase and user instructions</claudeMd>
<skill-format>true</skill-format>

10-Component Framework

1. Role Definition: Who is the AI acting as?
2. Context & Scope: What is covered and excluded?
3. Quick Start: How to get started immediately?
4. Core Concepts: Why does this approach work?
5. Behavioral Instructions: What should the AI do (or not do)?
6. Tool Use Guidelines: How should tools be invoked?
7. Output Format: What should responses look like?
8. Examples & Patterns: What do good implementations look like?
9. Error Handling: What to do when things fail?
10. Further Reading: Where to find more information?

Best Practices (DO/DON'T)

DO

✅ Use XML tags for structure - Provides clear delimiters for instructions ✅ Focus on content, not tag names - Clear instructions matter more than naming ✅ Combine complementary tags - Multiple tags for nuanced control ✅ Provide examples - Show good vs. bad patterns ✅ Specify scope clearly - In Scope vs. Out of Scope sections

DON'T

❌ Rely on tag name magic - <custom_tag> works as well as <official_tag> ❌ Over-specify edge cases - Let Claude reason within guidelines ❌ Use tags for simple formatting - Markdown is sufficient ❌ Nest XML tags deeply - Keep structure flat (1-2 levels max) ❌ Duplicate instructions - One clear statement > multiple vague ones

Common Patterns

Phase-Gated Workflow

<do_not_act_before_instructions>
Phase 1 (Planning): Read-only, no file modifications
Phase 2 (Execution): Requires `/01_confirm` command
</do_not_act_before_instructions>

Autonomous Execution

<default_to_action>Execute immediately when user request maps to clear tool usage.</default_to_action>
<use_parallel_tool_calls>Execute independent operations simultaneously.</use_parallel_tool_calls>

Quality Assurance

<investigate_before_answering>
Before analysis: Read files, search patterns, check documentation.
</investigate_before_answering>

Further Reading

Internal: @.claude/skills/claude-prompt-guide/REFERENCE.md - Detailed tag documentation, customization guide | @.claude/skills/claude-prompt-guide/EXAMPLES.md - Common patterns and 10-component framework examples | @.claude/skills/coding-standards/SKILL.md - Code quality standards | @.claude/agents/CONTEXT.md - Agent ecosystem | @.claude/commands/CONTEXT.md - Command workflows

External: Prompting best practices - Claude Docs | Use XML tags - Claude Docs | Claude Code Best Practices - Anthropic | Piebald-AI/claude-code-system-prompts - 40+ system prompt examples

Version: claude-pilot 4.4.43