Borrowing it
Nothing to install: this file belongs to chrisreddington/turn-based-game-mcp. 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/chrisreddington/turn-based-game-mcp/main/.github/instructions/custom-agents.instructions.mdgit clone --depth 1 https://github.com/chrisreddington/turn-based-game-mcpWrote 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/chrisreddington/turn-based-game-mcp/custom-agents)<a href="https://agentmods.dev/instructions/chrisreddington/turn-based-game-mcp/custom-agents"><img src="https://agentmods.dev/badge/instructions/chrisreddington/turn-based-game-mcp/custom-agents/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/chrisreddington/turn-based-game-mcp/custom-agents"><img src="https://agentmods.dev/badge/instructions/chrisreddington/turn-based-game-mcp/custom-agents.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 | $0.02494 | $0.02494 |
| Opus 5.5 | $0.00998 | $0.00998 |
| Sonnet 5.5 | $0.00499 | $0.00499 |
| Haiku 4.5 | $0.00249 | $0.00249 |
Grade B, and why
turn-based-game-mcp custom-agents.instructions.md scanned grade B with 1 finding 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 2mo 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.
Unrestricted tool accessmediumExcessive agency
A wildcard tool grant or "run any command" leaves no least-privilege boundary at all.
| `tools` | List of available tools (omit to enable all tools) | How it starts
The opening of the file, as written. The whole thing — 427 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Creating GitHub Copilot Custom Agents
Follow these guidelines when creating custom agent files (formerly known as chat modes).
Purpose
Custom agents configure AI behavior for specialized development tasks. Each agent defines a persona with specific tools, instructions, and workflow transitions. Use agents to create focused experiences like planners, reviewers, or implementation specialists.
File Location and Naming
Workspace Agents
- Location:
.github/agents/folder - Available to all workspace users
- Shared via version control
Naming Convention
- Use
.agent.mdextension - Filename becomes default agent name
- Allowed characters:
.,-,_,a-z,A-Z,0-9
.github/agents/
├── plan.agent.md
├── security-review.agent.md
└── test-specialist.agent.md
File Structure
Agent files have two parts: YAML frontmatter and Markdown body.
---
name: Agent Name
description: Brief description shown in chat input
tools: ['tool1', 'tool2']
---
# Agent Instructions
Your prompt and behavioral instructions go here.
YAML Frontmatter Properties
Required Properties
| Property | Description |
|---|---|
description |
Brief explanation shown as placeholder text in chat input |
Optional Properties
| Property | Description |
|---|---|
name |
Display name (defaults to filename without extension) |
argument-hint |
Hint text guiding users on how to interact |
tools |
List of available tools (omit to enable all tools) |
model |
AI model to use (e.g., Claude Sonnet 4) |
target |
Environment: vscode or github-copilot (omit for both) |
mcp-servers |
MCP server configs (org/enterprise agents only) |
handoffs |
Workflow transitions to other agents |
Tool Configuration
Restricting Tools
Specify tools to limit agent capabilities:
# Read-only agent - no code modifications
tools: ['search', 'fetch', 'read', 'usages', 'problems', 'changes']
# Full implementation agent
tools: ['search', 'read', 'edit', 'run', 'fetch']
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.
- 2mo ago First seen · 427 lines · 2,494 tokens per session scan B cb10539487b5
turn-based-game-mcp custom-agents.instructions.md is an instructions file published in the GitHub repository chrisreddington/turn-based-game-mcp (31 stars, last pushed 1mo ago), licensed MIT. It adds 2,494 tokens to every session, about $0.0100 per session on Opus 5.5. A static security scan graded it B with 1 finding (unrestricted tool access). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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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.
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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).
deno copilot-instructions.md
Copilot instructions for denoland/deno, covering deno development guide for github copilot, network access, high level overview, key directories and key files to understand first.