| name | prompt-optimizer |
| description | Optimize system prompts for Claude Code agents using proven prompt engineering patterns. Use when users request prompt improvement, optimization, or refinement for agent workflows, tool instructions, or system behaviors. |
Prompt Optimizer
Optimizes system prompts by applying research-backed prompt engineering patterns. Human-in-the-loop phases: understand, plan, propose changes, receive approval, then integrate.
Purpose and Success Criteria
A well-optimized prompt achieves:
- Behavioral clarity: Agent knows exactly what to do in common cases and edge cases
- Appropriate scope: Complex tasks get decomposition; simple tasks don't trigger overthinking
- Grounded changes: Every modification traces to a specific pattern with documented impact
Optimization is complete when:
- Every change has explicit pattern attribution from the reference document
- No section contradicts another section
- The prompt matches its operating context (tool-use vs. conversational, token constraints)
- Human has approved both section-level changes and full integration
When to Use This Skill
Use when the user provides a prompt and wants it improved, refined, or reviewed for best practices.
Do NOT use for:
- Writing prompts from scratch (different skill)
- Prompts that are already working well and user just wants validation
- Non-prompt content (documentation, code, etc.)
Required Resources
Before ANY analysis, read the appropriate pattern reference(s):
Single-Turn Reference (Always Read)
Read references/prompt-engineering-single-turn.md
Contains: Technique Selection Guide table, Quick Reference principles, domain-organized techniques with citations, Anti-Patterns section.
Multi-Turn Reference (Conditional)
Read references/prompt-engineering-multi-turn.md
Read ONLY when the prompt involves:
- Multi-turn flows (iterative refinement, conversation chains)
- Multi-agent / sub-agent orchestration
Skip for:
- Static system prompts executed in a single LLM call
- Tool instructions or one-shot prompts
Workflow Reference
Read references/workflow.md
Contains: Detailed Phase 0-4 workflows, visual card template, completion checkpoint.
Quick Process
┌─────────────────────────────────────────────────────────────────┐
│ 1. READ THE REFERENCE(S) │
│ - Always: references/prompt-engineering-single-turn.md │
│ - If multi-turn/multi-agent: also read multi-turn reference │
├─────────────────────────────────────────────────────────────────┤
│ 2. UNDERSTAND THE PROMPT (Phase 1) │
│ - Operating context (single-shot? tool-use? constraints?) │
│ - Current state (working? unclear? missing?) │
│ - Document specific problems with quoted prompt text │
├─────────────────────────────────────────────────────────────────┤
│ 3. PLAN WITH VISUAL CARDS (Phase 2) │
│ - Present each change as a visual card with: │
│ SCOPE → PROBLEM → TECHNIQUE → BEFORE/AFTER │
│ - Quote trigger conditions from reference │
│ - ⚠️ WAIT FOR USER APPROVAL before proceeding │
├─────────────────────────────────────────────────────────────────┤
│ 4. EXECUTE APPROVED CHANGES (Phase 3) │
│ - Apply the BEFORE → AFTER transformations │
├─────────────────────────────────────────────────────────────────┤
│ 5. INTEGRATE AND VERIFY QUALITY (Phase 4) │
│ - Check cross-section coherence │
│ - Final anti-pattern check │
│ - Present complete optimized prompt │
└─────────────────────────────────────────────────────────────────┘
Triage (Phase 0)
Simple prompts (use lightweight process):
- Under 20 lines
- Single clear purpose
- No conditional logic
Complex prompts (use full process):
- Multiple sections serving different functions
- Conditional behaviors or rule hierarchies
- Tool orchestration or multi-step workflows
Core Quality Principles
- Quote before deciding: Every technique selection must quote the reference's trigger condition.
- Open verification questions: Ask "What behavior will this produce?" not "Is this correct?"
- Approval happens once, upfront: The visual card format in Phase 2 shows full impact.
- Preserve what works: Optimization means improving problems, not rewriting everything.
Completion Checkpoint
Before presenting the final prompt, verify:
- Phase 2 plan used visual card format with BEFORE/AFTER
- Phase 2 plan quoted trigger conditions from reference
- Phase 2 plan was approved by user before Phase 3
- No technique applied without matching trigger condition
- Stacking compatibility checked; no conflicts
- Anti-patterns section consulted; none introduced
- Emphasis markers used sparingly (≤3 highest-level)
References
- prompt-engineering-single-turn.md - Single-turn patterns
- prompt-engineering-multi-turn.md - Multi-turn patterns
- workflow.md - Detailed phase workflows and card template