agent-world: Skill for Claude Code

.claude/skills/prompt-engineering-patterns/SKILL.md

prompt-engineering-patterns is a skill for Claude Code from nicepkg/agent-world. It costs 41 tokens per session (3,174 once invoked), scanned A, original, MIT.

A guide to writing instructions for AI language models so they produce more consistent and controllable results.

In plain words
What is it for?
Use it to design reusable prompts, choose examples, improve inconsistent outputs, request structured JSON, and create instructions for specialised AI assistants.
Why use it?
It helps reduce unclear, unreliable, or difficult-to-parse AI responses when building prompts for real applications.

Skill for Claude Code

Written for Claude Code: installed under .claude/.

This is nicepkg/agent-world's own configuration. It tells Claude Code how to work on agent-world itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything agent-world configures →

Reuse

Borrowing it

Nothing to install: this file belongs to nicepkg/agent-world. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/nicepkg/agent-world/main/.claude/skills/prompt-engineering-patterns/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/nicepkg/agent-world

Made for: Claude Code.

Wrote this? Show the measurements

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README.md
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Per session 41 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,174 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00041 $0.03174
Opus 5.5 $0.00016 $0.01270
Sonnet 5.5 $0.00008 $0.00635
Haiku 4.5 $0.00004 $0.00317

Measured 2mo ago against content hash 8d38ab4ac457, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

prompt-engineering-patterns scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2mo ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/optimize-prompt.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

.claude/skills/prompt-engineering-patterns/SKILL.md · 481 lines

How it starts

The opening of the file, as written. The whole thing — 481 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Prompt Engineering Patterns

Master advanced prompt engineering techniques to maximize LLM performance, reliability, and controllability.

When to Use This Skill

  • Designing complex prompts for production LLM applications
  • Optimizing prompt performance and consistency
  • Implementing structured reasoning patterns (chain-of-thought, tree-of-thought)
  • Building few-shot learning systems with dynamic example selection
  • Creating reusable prompt templates with variable interpolation
  • Debugging and refining prompts that produce inconsistent outputs
  • Implementing system prompts for specialized AI assistants
  • Using structured outputs (JSON mode) for reliable parsing

Core Capabilities

1. Few-Shot Learning

  • Example selection strategies (semantic similarity, diversity sampling)
  • Balancing example count with context window constraints
  • Constructing effective demonstrations with input-output pairs
  • Dynamic example retrieval from knowledge bases
  • Handling edge cases through strategic example selection

2. Chain-of-Thought Prompting

  • Step-by-step reasoning elicitation
  • Zero-shot CoT with "Let's think step by step"
  • Few-shot CoT with reasoning traces
  • Self-consistency techniques (sampling multiple reasoning paths)
  • Verification and validation steps

3. Structured Outputs

  • JSON mode for reliable parsing
  • Pydantic schema enforcement
  • Type-safe response handling
  • Error handling for malformed outputs

4. Prompt Optimization

  • Iterative refinement workflows
  • A/B testing prompt variations
  • Measuring prompt performance metrics (accuracy, consistency, latency)
  • Reducing token usage while maintaining quality
  • Handling edge cases and failure modes

5. Template Systems

  • Variable interpolation and formatting
  • Conditional prompt sections
  • Multi-turn conversation templates
  • Role-based prompt composition
  • Modular prompt components

6. System Prompt Design

  • Setting model behavior and constraints
  • Defining output formats and structure
  • Establishing role and expertise
  • Safety guidelines and content policies
  • Context setting and background information

Read the full file on GitHub · 481 lines

Files

What ships with it

8 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2mo ago First seen · 481 lines · 41 tokens per session scan A 8d38ab4ac457

Subscribe to this mod's changes

prompt-engineering-patterns is a skill published in the GitHub repository nicepkg/agent-world (6 stars, last pushed 8mo ago), licensed MIT. It adds 41 tokens to every session and 3,174 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.