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 sources

• patterns.md : Reusable patterns and templates

• examples.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