Borrowing it
Nothing to install: this file belongs to jonathan-vella/apex-accelerator. 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/jonathan-vella/apex-accelerator/main/.github/instructions/agent-skills.instructions.mdgit 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/instructions/jonathan-vella/apex-accelerator/agent-skills)<a href="https://agentmods.dev/instructions/jonathan-vella/apex-accelerator/agent-skills"><img src="https://agentmods.dev/badge/instructions/jonathan-vella/apex-accelerator/agent-skills/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/jonathan-vella/apex-accelerator/agent-skills"><img src="https://agentmods.dev/badge/instructions/jonathan-vella/apex-accelerator/agent-skills.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 | $0.01984 | $0.01984 |
| Opus 5.5 | $0.00794 | $0.00794 |
| Sonnet 5.5 | $0.00397 | $0.00397 |
| Haiku 4.5 | $0.00198 | $0.00198 |
Grade A, and why
apex-accelerator agent-skills.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 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 — 158 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Agent Skills File Guidelines
Agent Skills are folders of instructions, scripts, and resources that Copilot
loads on demand, following the Agent Skills open standard.
This file holds the enforced APEX rules; locations, body sections, directory layout,
progressive loading, writing style and the full context policy live in the
skill authoring reference.
Required SKILL.md Frontmatter
---
name: apex-webapp-testing
description: "Toolkit for testing local web apps using Playwright. Use when asked to verify frontend functionality, debug UI behavior, or capture screenshots."
---
| Field | Required | Constraints |
|---|---|---|
name |
Yes | Lowercase, hyphens for spaces, max 64 chars. Must match parent directory name. |
description |
Yes | State WHAT, WHEN, and KEYWORDS; platform max 1024 chars, APEX max 500 |
argument-hint |
No | Concise non-secret slash input hint; APEX: non-empty single line, max 160 chars |
user-invocable |
No | Boolean, default true. Set false to hide from / menu |
disable-model-invocation |
No | Boolean, default false. Set true to require manual / invocation only |
context |
No | inline (default) or experimental fork; omit for current APEX skills |
license |
No | Reference to LICENSE.txt or SPDX identifier |
Name matching rule: Repository-owned skills MUST use exactly one apex-
prefix, lowercase kebab-case, and at most 64 characters. The frontmatter name
MUST match its parent directory. If the directory is
.github/skills/apex-webapp-testing/, the name must be apex-webapp-testing.
Mismatched names prevent the skill from loading. Leave external user/plugin
skills unchanged; preserve upstream identity and attribution when adapting
repository-owned skills. Do not create wrapper skills to enforce the prefix.
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 Changed · +2 lines · +30 tokens per session e405ff1f2c36
- 6d ago Changed · +2 lines · +1 tokens per session cd0635b13ccd
- 1mo ago Changed · -71 lines · -740 tokens per session df9b34566384
- 1mo ago Changed · +49 lines · +731 tokens per session 45655a81719e
- 1mo ago First seen · 176 lines · 1,962 tokens per session scan A 6452c292e158
apex-accelerator agent-skills.instructions.md is an instructions file published in the GitHub repository jonathan-vella/apex-accelerator (50 stars, last pushed yesterday), licensed MIT. It adds 1,984 tokens to every session, about $0.0079 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.
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