Borrowing it
Nothing to install: this file belongs to AvdLee/Core-Data-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/Core-Data-Agent-Skill/main/.github/copilot-instructions.mdgit clone --depth 1 https://github.com/AvdLee/Core-Data-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/core-data-agent-skill/copilot-instructions)<a href="https://agentmods.dev/instructions/avdlee/core-data-agent-skill/copilot-instructions"><img src="https://agentmods.dev/badge/instructions/avdlee/core-data-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/core-data-agent-skill/copilot-instructions"><img src="https://agentmods.dev/badge/instructions/avdlee/core-data-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 | $0.01115 | $0.01115 |
| Opus 5.5 | $0.00446 | $0.00446 |
| Sonnet 5.5 | $0.00223 | $0.00223 |
| Haiku 4.5 | $0.00112 | $0.00112 |
Grade A, and why
Core-Data-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.
This is a copy
86% identical to Swift-Concurrency-Agent-Skill copilot-instructions.md — 20 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 100 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 · 100 lines · 1,115 tokens per session scan A 9b6b9abcb75c
Core-Data-Agent-Skill copilot-instructions.md is an instructions file published in the GitHub repository AvdLee/Core-Data-Agent-Skill (318 stars, last pushed 1mo ago), licensed MIT. It adds 1,115 tokens to every session, about $0.0045 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 86% identical to Swift-Concurrency-Agent-Skill copilot-instructions.md, differing in 20 lines, and is treated as a copy.
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Model-specific prompt authoring and registry guidelines.