Use it to write reusable Copilot Chat prompts for asking questions, editing code, or running agent-based tasks.

It helps prompts produce more predictable results by defining their purpose, agent, model, and available tools.

How dhar174/custom_github_copilot_agent_builder configures GitHub Copi

Q: What is custom_github_copilot_agent_builder prompt.instructions.md?

Guidance for creating GitHub Copilot prompt files, which are reusable instructions that developers can invoke in Copilot Chat for a specific task.

Reuse

Borrowing it

Nothing to install: this file belongs to dhar174/custom_github_copilot_agent_builder. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file

curl -O https://raw.githubusercontent.com/dhar174/custom_github_copilot_agent_builder/main/.github/instructions/prompt.instructions.md

Clone the repo

git clone --depth 1 https://github.com/dhar174/custom_github_copilot_agent_builder

Made for: GitHub Copilot.

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.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/dhar174/custom_github_copilot_agent_builder/prompt.svg)](https://agentmods.dev/instructions/dhar174/custom_github_copilot_agent_builder/prompt)

Your own site

<a href="https://agentmods.dev/instructions/dhar174/custom_github_copilot_agent_builder/prompt"><img src="https://agentmods.dev/badge/instructions/dhar174/custom_github_copilot_agent_builder/prompt.svg" alt="Measured on agentmods" height="20"></a>

Per session 1,195 This file is loaded in full into every session.

When invoked 1,195 The same file — it is already loaded in full.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

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.

Model	Per session	Once invoked
Fable 5.1	$0.01195	$0.01195
Opus 5	$0.00598	$0.00598
Sonnet 5	$0.00239	$0.00239
Haiku 4.5	$0.00120	$0.00120

Measured 3d ago against content hash 3ec80d94465a, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

custom_github_copilot_agent_builder prompt.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 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:

codebase prompt.instructions.md — 100% identical, 37 lines differ

.github/instructions/prompt.instructions.md · 89 lines

How it starts

The opening of the file, as written. The whole thing — 89 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Copilot Prompt Files Guidelines

Instructions for creating effective and maintainable prompt files that guide GitHub Copilot in delivering consistent, high-quality outcomes across any repository.

Scope and Principles

Target audience: maintainers and contributors authoring reusable prompts for Copilot Chat.
Goals: predictable behaviour, clear expectations, minimal permissions, and portability across repositories.
Primary references: VS Code documentation on prompt files and organization-specific conventions.

Frontmatter Requirements

Every prompt file should include YAML frontmatter with the following fields:

Required/Recommended Fields

Field	Required	Description
`description`	Recommended	A short description of the prompt (single sentence, actionable outcome)
`name`	Optional	The name shown after typing `/` in chat. Defaults to filename if not specified
`agent`	Recommended	The agent to use: `ask`, `edit`, `agent`, or a custom agent name. Defaults to current agent
`model`	Optional	The language model to use. Defaults to the currently selected model
`tools`	Optional	List of tool/tool set names available for this prompt
`argument-hint`	Optional	Hint text shown in chat input to guide user interaction

Guidelines

Use consistent quoting (single quotes recommended) and keep one field per line for readability and version control clarity
If tools are specified and the current agent is ask or edit, the default agent becomes agent
Preserve any additional metadata (language, tags, visibility, etc.) required by your organization

File Naming and Placement

Use kebab-case filenames ending with .prompt.md and store them under .github/prompts/ unless your workspace standard specifies another directory.
Provide a short filename that communicates the action (for example, generate-readme.prompt.md rather than prompt1.prompt.md).

Body Structure

Start with an # level heading that matches the prompt intent so it surfaces well in Quick Pick search.
Organize content with predictable sections. Recommended baseline: Mission or Primary Directive, Scope & Preconditions, Inputs, Workflow (step-by-step), Output Expectations, and Quality Assurance.
Adjust section names to fit the domain, but retain the logical flow: why → context → inputs → actions → outputs → validation.
Reference related prompts or instruction files using relative links to aid discoverability.

Read the full file on GitHub · 89 lines

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.

3d ago First seen · 89 lines · 1,195 tokens per session scan A 3ec80d94465a

Subscribe to this mod's changes

custom_github_copilot_agent_builder prompt.instructions.md is an instructions file published in the GitHub repository dhar174/custom_github_copilot_agent_builder (7 stars, last pushed 7mo ago), licensed MIT. It adds 1,195 tokens to every session, about $0.0060 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.

Building agents

codex AGENTS.md

AGENTS.md instructions for openai/codex, covering rust/codex-rs, the codex-core crate, code review rules, crate api surface and model visible context.

openai/codex · 5,182 tokens

vscode buildNext.instructions.md

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).

microsoft/vscode · 6,785 tokens

custom_github_copilot_agent_builder: Instructions file for GitHub Copilot