How do I install the Add Lesson skill?

Run npx skillmds@latest add diegosouzapw/add-lesson in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

What does the Add Lesson skill do?

Add a new lesson learned to shared rules and sync to context files. It is listed under Coding & Dev Tools on SkillMD.

Is Add Lesson safe to use?

This skill has not completed SkillMD's automated safety review yet. Independent scanners report: SkillSpector: PASS, Skill Scanner: PASS. Capability flags: reads secrets. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Add Lesson?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Add Lesson free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Add Lesson?

diegosouzapw (@diegosouzapw) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Add Lesson by diegosouzapw — Agent Skill

Name: Add Lesson
Rating: 4.666666666666667 (3 reviews)
Author: diegosouzapw

File contents

Add Lesson Skill

Add a new lesson learned to the shared rules.

Overview

When you discover a bug, mistake, or useful pattern, use this skill to document it so all agents learn from it.

Usage

/add-lesson

Prerequisites

Access to shared-rules/ and permission to run scripts/sync-rules.py.

Lesson Template

### YYYY-MM-DD - Brief Title

- **Issue**: What went wrong or was discovered
- **Root Cause**: Why it happened
- **Fix**: How it was fixed
- **Prevention**: Rule or check to prevent recurrence
- **Applies To**: all | claude | cursor | gemini
- **Files Changed**: List of affected files

Process

Gather information:
- What was the issue?
- What caused it?
- How was it fixed?
- How can we prevent it?
Add to lessons file:
- Open shared-rules/lessons-learned.md
- Add new entry at TOP of "Recent Lessons" section
- Use the template format
Run sync:
```
python scripts/sync-rules.py
```
Verify propagation:
- Check CLAUDE.md updated
- Check timestamp

Example

### 2026-01-22 - Task Tool Token Efficiency

- **Issue**: Spawning Claude workers via subprocess was expensive (~13k tokens overhead)
- **Root Cause**: Full context duplication to each subprocess
- **Fix**: Use native Task tool with context filtering
- **Prevention**: Always prefer Task tool over subprocess for Claude workers
- **Applies To**: claude
- **Files Changed**:
  - `.claude/skills/implement-task/SKILL.md`
  - `CLAUDE.md`

Archiving

After 30 days or when list gets long:

Move old lessons to "Archived Lessons" section
Keep for historical reference

Outputs

Updated shared-rules/ content and synced context files (e.g. CLAUDE.md).

Error Handling

If sync fails, do not proceed; resolve and rerun scripts/sync-rules.py.
If lesson template is incomplete, request the missing fields before adding.

Related Skills

/sync-rules - Sync shared rules into context files

---name: add-lessondescription: Add a new lesson learned to shared rules and sync to context files.---# Add Lesson SkillAdd a new lesson learned to the shared rules.## OverviewWhen you discover a bug, mistake, or useful pattern, use this skill to document it so all agents learn from it.## Usage```/add-lesson```## Prerequisites- Access to `shared-rules/` and permission to run `scripts/sync-rules.py`.## Lesson Template```markdown### YYYY-MM-DD - Brief Title- **Issue**: What went wrong or was discovered- **Root Cause**: Why it happened- **Fix**: How it was fixed- **Prevention**: Rule or check to prevent recurrence- **Applies To**: all | claude | cursor | gemini- **Files Changed**: List of affected files```## Process1. **Gather information**: - What was the issue? - What caused it? - How was it fixed? - How can we prevent it?2. **Add to lessons file**: - Open `shared-rules/lessons-learned.md` - Add new entry at TOP of "Recent Lessons" section - Use the template format3. **Run sync**: ```bash python scripts/sync-rules.py ```4. **Verify propagation**: - Check CLAUDE.md updated - Check timestamp## Example```markdown### 2026-01-22 - Task Tool Token Efficiency- **Issue**: Spawning Claude workers via subprocess was expensive (~13k tokens overhead)- **Root Cause**: Full context duplication to each subprocess- **Fix**: Use native Task tool with context filtering- **Prevention**: Always prefer Task tool over subprocess for Claude workers- **Applies To**: claude- **Files Changed**: - `.claude/skills/implement-task/SKILL.md` - `CLAUDE.md````## CategoriesLessons should be categorized by:- `all` - Applies to all agents- `claude` - Claude-specific- `cursor` - Cursor-specific- `gemini` - Gemini-specific## ArchivingAfter 30 days or when list gets long:- Move old lessons to "Archived Lessons" section- Keep for historical reference## Outputs- Updated `shared-rules/` content and synced context files (e.g. `CLAUDE.md`).## Error Handling- If sync fails, do not proceed; resolve and rerun `scripts/sync-rules.py`.- If lesson template is incomplete, request the missing fields before adding.## Related Skills- `/sync-rules` - Sync shared rules into context files

Frequently asked questions

Add Lesson