Swift Concurrency Agent Skill is a portable set of guidance for AI coding tools working with Swift's concurrency features. Developers use it to migrate to Swift 6, diagnose data races and isolation errors, write safer asynchronous code, and improve concurrency performance. The catalogue entries package the project's plugin, skill, and instructions for supported agents.
Borrowing it
Nothing to install: this file belongs to AvdLee/Swift-Concurrency-Agent-Skill. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/AvdLee/Swift-Concurrency-Agent-Skill/main/.github/copilot-instructions.mdgit clone --depth 1 https://github.com/AvdLee/Swift-Concurrency-Agent-SkillWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/instructions/avdlee/swift-concurrency-agent-skill/copilot-instructions)<a href="https://agentmods.dev/instructions/avdlee/swift-concurrency-agent-skill/copilot-instructions"><img src="https://agentmods.dev/badge/instructions/avdlee/swift-concurrency-agent-skill/copilot-instructions/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/instructions/avdlee/swift-concurrency-agent-skill/copilot-instructions"><img src="https://agentmods.dev/badge/instructions/avdlee/swift-concurrency-agent-skill/copilot-instructions.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.01003 | $0.01003 |
| Opus 5.5 | $0.00401 | $0.00401 |
| Sonnet 5.5 | $0.00201 | $0.00201 |
| Haiku 4.5 | $0.00100 | $0.00100 |
Grade A, and why
Swift-Concurrency-Agent-Skill copilot-instructions.md 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 1mo ago.
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.
Copies of this mod
1 near-identical copy found in the catalogue:
- Core-Data-Agent-Skill copilot-instructions.md — 86% identical, 20 lines differ
How it starts
The opening of the file, as written. The whole thing — 94 lines — stays where its author put it; the contents beside it link to each section on GitHub.
GitHub Copilot Instructions: Agent Skills Expert
Review code changes as an Agent Skills expert, focusing on the Agent Skills open format specification and best practices.
Core Agent Skills Principles
Format Compliance
- SKILL.md structure: Every skill must have a
SKILL.mdfile with YAML frontmatter containingnameanddescriptionfields - YAML frontmatter requirements:
name: Maximum 64 characters, lowercase letters/numbers/hyphens only, no XML tags, cannot contain "anthropic" or "claude"description: Non-empty, maximum 1024 characters, no XML tags, must describe both what the skill does AND when to use it
- Progressive disclosure: Skills should be organized in levels (metadata → instructions → resources) to minimize context window usage
- Filesystem-based architecture: Skills exist as directories; files are loaded on-demand via bash commands, not all at once
Skill Content Organization
Level 1: Metadata (always loaded)
- YAML frontmatter in SKILL.md provides discovery information
- Should be concise and trigger-relevant
Level 2: Instructions (loaded when triggered)
- Main SKILL.md body contains procedural knowledge, workflows, best practices
- Should be under ~5k tokens
- Include decision trees, quick reference guides, and clear examples
Level 3: Resources (loaded as needed)
- Additional markdown files for specialized guidance
- Executable scripts for deterministic operations
- Reference materials (schemas, templates, examples)
- Only accessed when referenced, not loaded into context upfront
Review Focus Areas
-
Description Quality
- Does the description clearly state what the skill does?
- Does it specify when an agent should use this skill (trigger conditions)?
- Is it specific enough for accurate skill selection?
-
Instruction Clarity
- Are instructions actionable and step-by-step?
- Do they include decision trees or quick reference guides?
- Are code examples clear and correct?
- Is there a clear "how to use" section?
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.
- 1mo ago First seen · 94 lines · 1,003 tokens per session scan A 53fbf90c774a
Swift-Concurrency-Agent-Skill copilot-instructions.md is an instructions file published in the GitHub repository AvdLee/Swift-Concurrency-Agent-Skill (1,694 stars, last pushed 1mo ago), licensed MIT. It adds 1,003 tokens to every session, about $0.0040 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 2026-08-30.
Other instructions, from other repositories
vscode buildNext.instructions.md
Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).
next.js AGENTS.md
AGENTS.md instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, cache eligibility and rollout and applying the notice (cutover).
langchain AGENTS.md
AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.
vscode copilot-instructions.md
Copilot instructions for microsoft/vscode, covering vs code copilot instructions, project overview, root folders, core architecture (src/ folder) and built-in extensions (extensions/ folder).
vscode model-prompts.instructions.md
Model-specific prompt authoring and registry guidelines.