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 instructions/dhar174/custom_github_copilot_agent_builder/copilot-instructionsgit clone --depth 1 https://github.com/dhar174/custom_github_copilot_agent_builderWhat 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 | $0.00586 | $0.00586 |
| Opus 5 | $0.00293 | $0.00293 |
| Sonnet 5 | $0.00117 | $0.00117 |
| Haiku 4.5 | $0.00059 | $0.00059 |
Grade A, and why
custom_github_copilot_agent_builder copilot-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 2d 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 — 89 lines — stays where its author put it; the contents beside it link to each section on GitHub.
GitHub Copilot Instructions
Repository-Wide Instructions
This file contains repository-wide instructions for GitHub Copilot to improve code suggestions and agent behavior across the entire project.
Code Style and Conventions
General Guidelines
- Write clear, self-documenting code
- Follow language-specific best practices
- Prioritize readability and maintainability
- Use meaningful variable and function names
Documentation
- Use Markdown for all documentation files
- Keep documentation up-to-date with code changes
- Include examples where appropriate
- Follow the established documentation structure
Custom Agents
- Define custom agents in
.agent.mdfiles within.github/agents/ - Include clear purpose and capabilities for each agent
- Document agent usage patterns
- Test agents before committing
File Organization
Documentation Structure
docs/specs/: Technical specificationsdocs/context/: Context-specific documentationdocs/memory/: Persistent memory and learnings
GitHub Copilot Configuration
.github/copilot-instructions.md: This file (repo-wide instructions).github/instructions/: Path-specific instructions.github/agents/: Custom agent definitions.github/prompts/: Reusable prompt templates
Custom Agent Guidelines
When creating or modifying custom agents:
- Purpose: Clearly define the agent's purpose and scope
- Capabilities: List specific capabilities and tools available
- Examples: Provide usage examples
- Limitations: Document known limitations
- Testing: Include test scenarios
Prompt Guidelines
When creating prompt files (.prompt.md):
- Structure: Use clear section headers
- Parameters: Document any variables or parameters
- Context: Include necessary context
- Examples: Show example usage
- Expected Output: Describe expected results
Memory and Context Guidelines
Context Files (.context.md)
- Keep context focused and relevant
- Update regularly
- Remove outdated information
- Link to related files
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.
- 2d ago First seen · 89 lines · 586 tokens per session scan A f1fde7f65236
custom_github_copilot_agent_builder copilot-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 586 tokens to every session, about $0.0029 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 2026-08-31.
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