agent-customization

agent-customization is a skill for Claude Code from microsoft/vscode. It costs 193 tokens per session (1,270 once invoked), scanned A, original, MIT.

A general guide for creating, updating, reviewing, and troubleshooting files that customise a coding agent. These files include project instructions, prompts, custom agents, hooks, and reusable skills.

In plain words
What is it for?
Use it to save coding preferences, configure file-specific rules, create specialised agents, automate lifecycle actions, or package workflows.
Why use it?
It helps you choose the right kind of customisation and find out why a rule or workflow is not being applied.

Skill for Claude Code ✓ vendor

Written for Claude Code: user-invocable in frontmatter. Also seen: reads .claude/ paths; mentions subagents; mentions AGENTS.md.

Good fit Use it to save coding preferences, configure file-specific rules, create specialised agents, automate lifecycle actions, or package workflows.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/microsoft/vscode/agent-customization
About the project

Visual Studio Code is a code editor that supports editing, navigating, understanding, debugging, and extending software projects. Developers use it for the edit-build-debug cycle, and the catalogue add-ons provide skills, instructions, and agents for working within the editor.

microsoft/vscode · 191,195 stars · on GitHub · code.visualstudio.com

Install

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.

Any agent
npx skills add microsoft/vscode --skill agent-customization
Clone the repo
git clone --depth 1 https://github.com/microsoft/vscode

Made for: Claude Code.

Wrote 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.

agentmods badge for agent-customization

README.md
[![agentmods](https://agentmods.dev/badge/skills/microsoft/vscode/agent-customization.svg)](https://agentmods.dev/skills/microsoft/vscode/agent-customization)
Your own site
<a href="https://agentmods.dev/skills/microsoft/vscode/agent-customization"><img src="https://agentmods.dev/badge/skills/microsoft/vscode/agent-customization.svg" alt="Measured on agentmods" height="20"></a>
Per session 193 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,270 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. Third-party audits
  • Snyk pass 7 Sept 2026
How audits are shown
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 $0.00193 $0.01270
Opus 5 $0.00097 $0.00635
Sonnet 5 $0.00039 $0.00254
Haiku 4.5 $0.00019 $0.00127

Measured 3d ago against content hash c065f5b456a9, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

agent-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 3d 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.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

extensions/copilot/assets/prompts/skills/agent-customization/SKILL.md · 84 lines

How it starts

The opening of the file, as written. The whole thing — 84 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Agent Customization

Decision Flow

Primitive When to Use
agent instructions Always-on, applies everywhere in the project
File Instructions Explicit via applyTo patterns, or on-demand via description
MCP Integrates external systems, APIs, or data
Hooks Deterministic shell commands at agent lifecycle points (block tools, auto-format, inject context)
Custom Agents Subagents for context isolation, or multi-stage workflows with tool restrictions
Prompts Single focused task with parameterized inputs
Skills On-demand workflow with bundled assets (scripts/templates)

Quick Reference

Consult the reference docs for templates, domain examples, advanced frontmatter options, asset organization, anti-patterns, and creation checklists. If the references are not enough, load the official documentation links for each primitive.

Type File Location Reference
agent instructions copilot-instructions.md, AGENTS.md .github/ or root Link
File Instructions *.instructions.md .github/instructions/ Link
Prompts *.prompt.md .github/prompts/ Link
Hooks *.json .github/hooks/ Link
Custom Agents *.agent.md .github/agents/ Link
Skills SKILL.md .github/skills/<name>/, .agents/skills/<name>/, .claude/skills/<name>/ Link

User-level: {{VSCODE_USER_PROMPTS_FOLDER}}/ (*.prompt.md, *.instructions.md, *.agent.md; not skills) Customizations roam with user's settings sync

Creation Process

If you need to explore or validate patterns in the codebase, use a read-only subagent. If the ask-questions tool is available, use it to interview the user and clarify requirements.

Follow these steps when creating any customization file.

Read the full file on GitHub · 84 lines

Files

What ships with it

6 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. 3d ago First seen · 84 lines · 193 tokens per session scan A c065f5b456a9

Subscribe to this mod's changes

agent-customization is a skill published in the GitHub repository microsoft/vscode (191,195 stars, last pushed today), licensed MIT. It adds 193 tokens to every session and 1,270 once invoked, about $0.0010 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 2026-09-03.

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