AGENTS.md Improver
Overview
Maintain concise project instructions for AGENTS.md-compatible tools such as Codex, Copilot, Cursor, and similar coding agents.
Core principle: Find the effective instruction source -> extract durable learnings -> propose compact diffs -> apply approved changes only.
Announce at start: "I'm using the agents-md-improver skill to maintain concise AGENTS.md project instructions."
Prerequisites
- A repository or workspace with
AGENTS.md, nestedAGENTS.md, or compatible instruction files. - A user request to audit, improve, revise, migrate, or capture learnings into project instructions.
Workflow
Phase 1: Identify Instruction Targets
Find instruction files from the repository root:
find . \( -name "AGENTS.md" -o -name "CLAUDE.md" -o -name ".claude.local.md" \) 2>/dev/null | head -50
Use these targeting rules:
./AGENTS.md: primary shared project instructions for AGENTS.md-compatible tools.- Nested
AGENTS.md: module-specific instructions; update only when the learning applies to that subtree. - Include-only
AGENTS.md: if it contains only an include such as@./CLAUDE.md, read the target and treat that target as the effective source. Update the target only when the repository intentionally shares one instruction file across tools. CLAUDE.md: Claude Code-specific instructions, or a shared source whenAGENTS.mdintentionally points to it. Do not update it just because it exists..claude.local.md: personal Claude Code local notes. Do not create or edit it for shared AGENTS.md project memory.- User/global instruction files, such as
~/.codex/AGENTS.md: update only when the user explicitly asks for global behavior. .project_context/: historical exploration, plans, and execution summaries. Use it for trace records, not agent steering instructions.
If no AGENTS.md exists, propose creating the narrowest useful one, usually ./AGENTS.md.
Phase 2: Choose The Mode
Choose exactly one primary mode before scanning or proposing edits:
- Repository Audit Mode: use when the user asks whether instructions are stale, incomplete, inaccurate, outdated, or should be refreshed against the current repository. Then read references/repository-audit.md.
- Session Learning Mode: use when the user asks to capture this session's learnings, revise instructions from the current conversation, or preserve newly discovered repo-specific behavior. Then read references/session-learning.md.
- Migration Mode: use when moving useful guidance from
CLAUDE.mdor another tool-specific instruction file into an AGENTS.md-compatible source. Reuse Session Learning Mode for extraction rules, but keep tool-only slash commands, hooks, or UI shortcuts in tool-specific files unless the user asks to make them shared.
Phase 3: Draft Compact Updates
AGENTS.md is prompt context. Prefer dense, operational bullets.
Good format:
- Use `rg` for repo-wide search; fall back only if unavailable.
- Run `pnpm test -- --runInBand` for flaky integration tests in this repo.
- Keep API compatibility normalization in the service layer unless a spec explicitly changes request validation.
Avoid adding:
- generic engineering advice;
- one-off debugging details unlikely to recur;
- unverified assumptions or stale guesses;
- long explanations, logs, secrets, tokens, private URLs, or machine-specific credentials;
- duplicates of existing instructions.
Phase 4: Propose Before Editing
Always show proposed changes before modifying files. Group proposals by target file.
Use this format:
### Update: ./AGENTS.md
Why: <one-line reason this helps future agent sessions>
```diff
+ <concise addition>
```
If multiple files could be updated, explain the placement tradeoff:
- root
AGENTS.mdfor project-wide behavior; - nested
AGENTS.mdfor module-local behavior; .project_context/for historical records;CLAUDE.mdonly for Claude Code-specific behavior or an intentional shared source.
Ask for approval before editing. If the user already explicitly said to apply changes, proceed with the smallest safe patch.
Phase 5: Apply Carefully
When approved:
- use minimal patches and preserve the file's existing organization;
- insert under an existing relevant heading when possible;
- create a short new heading only if no suitable section exists;
- do not reorder unrelated content;
- do not remove or rewrite existing instructions unless the user asked for cleanup or the instruction is clearly obsolete;
- after editing, re-read the changed section and report exactly what changed.
Common Mistakes
- Treating
.project_context/as agent steering context. It is for traceability, not instructions that should load every session. - Updating
CLAUDE.mdfor a shared AGENTS.md request when the repo does not intentionally share one source file. - Missing an include-only
AGENTS.mdand patching the wrapper instead of the effective source. - Capturing logs, secrets, private URLs, or one-off debugging notes as durable instructions.
- Adding broad best practices that any competent agent already knows.
Output
For Repository Audit Mode, provide the quality report format from references/repository-audit.md.
For Session Learning Mode or Migration Mode, provide:
- files changed;
- concise summary of additions;
- any skipped proposals and why.
References
- repository-audit.md - Repository scan scope, quality criteria, and report template for stale or incomplete instructions.
- session-learning.md - Session learning extraction rules and concise update proposal template.
Source: hashgraph-online/awesome-codex-plugins → plugins/yyykf/spellbook-skills/skills/agents-md-improver/SKILL.md