agents-md

name

agents-md

description

Use this skill for any request to create, update, review, or improve files that guide AI coding tools—like AGENTS.md, Copilot context files, or agent instructions. Trigger when users want to help AI generate code that matches project conventions, avoids common mistakes, or understands non-obvious rules—whether for a whole repo, a subdirectory, or a specific component. Also use for queries about setting up Copilot or Cursor context, onboarding AI to team practices, or keeping agent guidance up to date—even if AGENTS.md isn't mentioned by name.

AGENTS.md Skill

AGENTS.md is the README for AI coding agents — it gives tools like GitHub Copilot, Cursor, and Claude Code the context they need to produce code that fits your project, without constant back-and-forth correction.

The Golden Rule: Only Include Non-Obvious Things

This is the most important principle. Before adding any line, ask: "Could an agent figure this out by reading the code or config files?"

If yes — skip it. Agents can read package.json, pyproject.toml, *.csproj, directory structures, imports, and existing code. AGENTS.md is for the things that aren't visible there:

• Project-specific conventions not enforced by any linter or analyzer
• "Never do X" patterns that look reasonable but are wrong in this codebase
• Commands that are non-standard or require project-specific flags
• Domain terminology or architectural choices that need explanation
• Common mistakes agents actually make here (discovered from experience)
• Security constraints and rules that must never be violated

Redundant content actively degrades quality — it wastes the agent's context window and dilutes real signal with noise it already has.

Two Shapes of AGENTS.md

Root-level AGENTS.md (repo root)

Covers the whole project: stack, layout, cross-cutting rules, major patterns, and a doc index. Aim for ≤ 150 lines. Link to existing guides rather than duplicating them. Include a short maintenance note telling agents to update related AGENTS.md files and relevant SKILL.md files when a new non-obvious pattern is introduced or existing guidance is stale, but to ask the user for permission before editing those guidance files.

Component-level AGENTS.md (subdirectory)

Scoped to one module, package, or concern (e.g., src/Api/, tests/). Create one when:

• The component has non-obvious rules not covered by the root file
• It has its own commands, stack, or lifecycle
• Agents working in that folder would benefit from a tightly-focused cheat sheet

Don't create a component AGENTS.md just for completeness. An empty or trivially short file adds nothing — it just adds noise to the file tree.

---

Root-Level Structure

# <Project Name> — Agent Instructions

## Quick Reference
- **Stack**: List of key technologies
- **Solution/Entry point**: Main file or solution
- **Common commands**: `build`, `test`, `run`, `format` — exact, copy-paste ready
- **Docs**: Links to key guides

## Repository Map
Folder → one-line purpose. Skip folders whose purpose is obvious from the name.

## Major Patterns
Bullet list of architectural decisions agents must know:
- Why a pattern is used (not just that it's used)
- Any non-obvious integration approaches

## Code Rules (MUST follow)
✅/❌ table — see format below.

## Common Mistakes
Concrete anti-patterns agents get wrong in this codebase. Not generic advice.

## Quick Troubleshooting
"Symptom → fix" pairs for problems agents are likely to hit.

Component-Level Structure

# <Component Name> — Agent Instructions

## Quick Reference
- **Scope**: `path/to/component/**`
- **Stack**: Techs specific to this component (only if different from root)
- **Commands**: Commands specific to this component

## Key Rules (MUST follow)
✅/❌ table — see format below.

## Common Mistakes
What agents get wrong specifically inside this component.

## Project Layout
Table: path → purpose. Skip obvious paths.

## Quick Troubleshooting
Symptom → fix pairs.

## Documentation Index
Table: topic → guide path. Don't repeat links from root AGENTS.md unless critical.

---

The ✅/❌ Rule Format

Rules work best as a short code block with ✅ for the right pattern and ❌ for the wrong one, side-by-side. This format is instantly scannable and makes the do/don't unambiguous:

✅ Guid.CreateVersion7()          ❌ Guid.NewGuid()
✅ DateTimeOffset.UtcNow          ❌ DateTime.Now
✅ record EventPastTense(...)     ❌ record VerbCommand(...)
✅ [LoggerMessage(...)]           ❌ _logger.LogInformation(...)

Rules that belong here:

• API/library choices where the wrong option compiles fine but violates project policy
• Naming conventions that linters don't enforce
• Framework-level gotchas specific to this codebase

Rules to skip:

• Things already caught by error-producing analyzers (the build will stop them anyway)
• Generic best practices any senior dev knows ("don't hardcode secrets", "use async")
• Anything an agent would infer from reading existing code

---

Content Priority Filter

Run every candidate line through this filter before including it:

Question	If YES	If NO
Would an agent deduce this from reading the files?	Skip	Include
Does a linter or analyzer already enforce this?	Skip	Include
Is this generic advice true of any codebase?	Skip	Include
Would an agent without this make a real mistake here?	Include	Skip
Is this specific to this codebase's conventions?	Include	Skip

---

Single Source of Truth

Don't duplicate content from README, wikis, or existing docs. Link to them:

## Documentation Index
| Topic | Guide |
|-------|-------|
| Architecture | `docs/architecture.md` |
| Testing patterns | `docs/guides/testing-guide.md` |

This keeps AGENTS.md focused and avoids stale duplication. If two files say the same thing and one gets updated, they immediately diverge.

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Treat It as Living Code

Update AGENTS.md in the same PR as the change it documents. If tests now require a specific flag, a linter is added, or a pattern changes — the AGENTS.md update belongs in that diff. If the change also makes a scoped AGENTS.md or a related SKILL.md stale, update those guidance files too. Ask the user for permission before editing any guidance file. Reviewers should check AGENTS.md freshness as part of code review.

---

Checklist Before Saving

• Every ✅/❌ rule is non-obvious (an agent wouldn't know it without being told)
• No content duplicated from README or other docs — linked instead
• All commands are copy-paste ready, wrapped in backticks
• Root AGENTS.md ≤ 150 lines; component AGENTS.md ≤ 100 lines
• No generic advice ("write clean code", "handle errors")
• Each "Common Mistake" names a specific anti-pattern, not a vague category
• Root AGENTS.md tells agents to refresh related AGENTS/skills when guidance goes stale
• Root AGENTS.md tells agents to ask the user before editing AGENTS.md or SKILL.md files
• Every section passes the Content Priority Filter