prompt-engineering

name	prompt-engineering
description	Use this skill when designing, critiquing, or fixing system prompts, tool descriptions, skill definitions, or LLM instruction text in WrongStack. Triggers: user mentions "prompt", "system instruction", "skill description", "tool hint", "usage hint", "system prompt".
version	1.1.0

Prompt Engineering — WrongStack

Overview

Designs, critiques, and fixes system prompts, tool descriptions, and skill definitions for LLM agents. WrongStack uses a 4-layer prompt structure — static content first, volatile last for cache efficiency.

Rules

1. Static content first, volatile last — cache-friendly prompts cost less per token.
2. First sentence of skill description = trigger — keep it specific and actionable.
3. Tool descriptions must say: when to use, key parameters, what it returns.
4. Remove filler ("Please be helpful", "Sure, I'd be happy to") — wastes tokens.
5. Always read before edit — agents should grep/read first, then edit.
6. Skill descriptions should list specific trigger keywords, not generic descriptions.

Patterns

Do

# ✅ Good — specific trigger
Use this skill when writing or reviewing React 19+ code.

# ✅ Good — tool description with all three parts
Search file contents with regex. Pattern is regex. Use output_mode to select
content (matched lines), files_with_matches (file list), or count (line counts).
Always read before edit — grep first to locate the target.

# ✅ Good — skill description with trigger keywords
Use this skill when designing system prompts or tool descriptions
for LLM agents. Covers structure, specificity, and common pitfalls.
Triggers: user mentions "prompt", "system instruction", "tool hint".

Don't

# ❌ Bad — vague trigger
This skill is about Docker.

# ❌ Bad — filler
Please be helpful and use your best judgment.

# ❌ Bad — tool description missing parameters
Search files using grep.

WrongStack's 4-layer structure

Layer 1: Identity     — Who you are (static, cacheable)
Layer 2: Tool usage   — Available tools and their usage hints (static)
Layer 3: Environment  — Project context, skills, modes, plan (semistatic)
Layer 4: Volatile     — Session state, recent errors, mode prompt (dynamic)

Static content first. Volatile content last. Cache-friendly prompts cost less per token.

Trigger sentences (skill descriptions)

The first sentence of a skill description is its trigger. This is the only thing the skill loader matches on.

# Good — specific trigger
Use this skill when deploying Docker containers to staging.

# Bad — vague
This skill is about Docker.

# Good — pattern matchable
Use this skill when writing or reviewing React 19+ code.

# Bad — not actionable
This skill covers modern React patterns.

Tool description rules

Every tool in WrongStack has: name, description, usageHint, inputSchema.

The usageHint is what appears in the system prompt. It must say:

1. When to use it — not just what it does
2. Key parameters — the important inputs
3. What it returns — so the model knows what to do next

# Good
Search file contents with regex. Pattern is regex. Use output_mode to select
content (matched lines), files_with_matches (file list), or count (line counts).
Always read before edit — grep first to locate the target.

# Bad
Search files using grep.

Common tool chain patterns (for system prompt builder)

Inspect → Edit:    glob/read → locate → edit
Search → Operate:   grep/glob → identify → batch_tool_use or edit
Verify → Report:    write/edit/patch → read back → confirm
Batch Replace:     grep with pattern → replace with glob → verify

Anti-patterns

Anti-pattern	Why it's bad	Fix
"Please be helpful"	Wastes tokens, implies the model isn't	Remove it
"You are a helpful AI"	Already implied by default identity	Remove it
"Sure, I'd be happy to"	Same — filler, no information	Remove it
Vague parameter docs	Model doesn't know when to use tool	Add concrete examples
Long preamble before the question	Model reads it, then reads the actual question	Put question first
Ambiguous pronouns	"do it again" — which tool, which file?	Name the specific thing

Skill SKILL.md rules

See skill-creator skill for the format. Key points:

• First sentence = trigger condition
• Include concrete code examples in "Do" and "Don't" sections
• End with "Skills in scope" so agents know to delegate

Skills in scope

• skill-creator — for creating new skills (primary — prompt-engineering feeds into skill creation)
• typescript-strict — for TypeScript-specific prompt typing
• react-modern — for React component prompt conventions