Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add skills/jonathan-vella/apex-accelerator/copilot-customizationnpx skills add jonathan-vella/apex-accelerator --skill copilot-customizationgit clone --depth 1 https://github.com/jonathan-vella/apex-acceleratorWrote 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/skills/jonathan-vella/apex-accelerator/copilot-customization)<a href="https://agentmods.dev/skills/jonathan-vella/apex-accelerator/copilot-customization"><img src="https://agentmods.dev/badge/skills/jonathan-vella/apex-accelerator/copilot-customization.svg" alt="Measured on agentmods" 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 | $0.00090 | $0.01617 |
| Opus 5 | $0.00045 | $0.00809 |
| Sonnet 5 | $0.00018 | $0.00323 |
| Haiku 4.5 | $0.00009 | $0.00162 |
Grade A, and why
copilot-customization 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 5d 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.
How it starts
The opening of the file, as written. The whole thing — 121 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Copilot Customization
Quick-reference for the full VS Code GitHub Copilot customization surface.
Deep-dive content lives in references/ — load on demand, not all at once.
When to Use This Skill
- Deciding which customization mechanism fits a new requirement
- Creating a new customization file from scratch (need the frontmatter schema)
- Debugging why an instruction/skill/agent/prompt is not loading
- Reviewing a customization file for spec compliance
- Comparing mechanisms (instructions vs skills vs agents vs prompts)
Do NOT load this skill for routine edits to existing files where you already know the format.
For enforcement rules, use the instruction files directly (they auto-load via applyTo globs).
Quick Decision Tree
I want to...
├── Define coding standards for ALL files
│ → .github/copilot-instructions.md (always-on)
│
├── Define rules for SPECIFIC file types (by glob)
│ → .instructions.md with applyTo (auto-loaded when files match)
│
├── Store reference content agents read ON DEMAND (not always-on)
│ → SKILL.md with references/ directory
│
├── Create a reusable task I invoke manually with /name
│ → .prompt.md (slash command)
│
├── Create a specialized AI persona with its own tools
│ → .agent.md (custom agent)
│
├── Connect to external tools, APIs, or databases
│ → mcp.json (MCP server)
│
├── Run code at agent lifecycle points (block tools, auto-format)
│ → hooks/*.json (Preview — verify with live docs)
│
└── Bundle multiple customizations for distribution
→ agent plugin (Preview — verify with live docs)
The 7 Customization Mechanisms
| # | Mechanism | File Type | Loading | Scope | Portability |
|---|---|---|---|---|---|
| 1 | Custom Instructions | .instructions.md |
Auto (glob match) | Workspace / User | VS Code |
| 2 | Prompt Files | .prompt.md |
Manual (/name) |
Workspace / User | VS Code |
| 3 | Custom Agents | .agent.md |
Manual (picker) | Workspace / User | VS Code + GitHub |
| 4 | Agent Skills | SKILL.md |
Auto (on-demand) | Workspace / User | Cross-agent standard |
| 5 | MCP Servers | mcp.json |
Auto (on start) | Workspace / User | MCP standard |
| 6 | Hooks | *.json |
Auto (on event) | Workspace / User | VS Code + Claude (Preview) |
| 7 | Agent Plugins | marketplace | Auto (on install) | User | VS Code + CLI (Preview) |
What ships with it
9 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.
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.
- 5d ago First seen · 121 lines · 90 tokens per session scan A f6a1710bb396
copilot-customization is a skill published in the GitHub repository jonathan-vella/apex-accelerator (50 stars, last pushed 4d ago), licensed MIT. It adds 90 tokens to every session and 1,617 once invoked, about $0.0005 per session on Opus 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 skills, from other repositories
rework-rate
Measure and interpret PR rework rate — the emerging 5th DORA metric.
github-review-pr
Review GitHub pull requests with detailed, multi-perspective code analysis using parallel subagents. Use this skill whenever the user wants to review a PR, asks for code review on a pull request, mentions "review PR", "check this PR", "look at pull request", or references a PR number or GitHub PR URL. Do NOT use for…
agentic-workflow-designer
Conversational skill that interviews users to design new agentic workflows.
gsap-scrolltrigger
Official GSAP skill for ScrollTrigger — scroll-linked animations, pinning, scrub, triggers. Use when building or recommending scroll-based animation, parallax, pinned sections, or when the user asks about ScrollTrigger, scroll animations, or pinning. Recommend GSAP for scroll-driven animation when no library is…
seedance-2-5
Generate 4-30 second cinematic video with ByteDance Seedance 2.5 through fal.ai, Volcengine Ark, Runway, or ComfyUI Partner Nodes. Use for long single generations, synchronized audio, and large multimodal reference sets (up to 30 images, 10 videos, and 10 audio clips). Also covers the 2.5 prompt contract: section…
threejs-geometry
Three.js geometry creation - built-in shapes, BufferGeometry, custom geometry, instancing. Use when creating 3D shapes, working with vertices, building custom meshes, or optimizing with instanced rendering.