Claude Prompt Engineering
Knowledge snapshot from: 2026-02-20 Generated by: cogworks
Overview
This skill provides practical, Claude-specific prompt engineering guidance for Opus 4.6, Sonnet 4.5, and Haiku 4.5. It emphasizes fast model-aware decisions: reasoning mode selection, context management, safe autonomy, tool efficiency, and output control.
When to Use This Skill
Use this skill when you need to:
- Design or review Claude system prompts
- Tune adaptive or extended thinking behavior
- Improve tool orchestration and parallelization
- Handle long-horizon or multi-window workflows
- Add prompt-injection and data-leakage safeguards
- Reduce verbosity while preserving answer quality
Quick Decision Cheatsheet
- Opus 4.6: Use adaptive thinking (
low|medium|high|max) only when task complexity justifies it. - Sonnet 4.5: Use extended thinking for legacy workflows; minimum budget 1024 tokens.
- Simple tasks: Prefer no explicit thinking config.
- Long tasks: Persist state in files + git checkpoints.
- Independent reads/searches: Run tool calls in parallel.
- Risky/irreversible actions: Ask for confirmation first.
- Production exposure: Apply defense-in-depth (input, architecture, output).
Supporting Docs
reference.md: Canonical guidance, decision rules, anti-patterns, and sourcespatterns.md: Reusable patterns and templatesexamples.md: Compact before/after prompt examples
Model Routing Contract
- primary-capability-class: reasoning
- fallback-capability-class: workhorse
- task-to-capability mapping:
- source ingestion/extraction: workhorse - synthesis/contradiction resolution: reasoning - final skill drafting: workhorse
- quality gates tied to capability:
- reasoning: resolve contradictions and justify the interpretation - workhorse: complete structure with citations and no stubs
- runtime model resolution:
- map capability classes to provider/runtime defaults automatically - never ask the user to choose a model
Invocation
/claude-prompt-engineering