Build and test a focused skill.
Combine discovery metadata, a bounded procedure and positive and negative test cases.
Read the descriptive transcript
Follow the complete narration and the changes shown in the video. Each example can be copied.
1. A skill packages a repeatable procedure.
A skill combines discovery metadata with instructions for a specific task. This is a short excerpt of a skill file. The complete example and exercise on the page add input, procedure, output, and boundaries.
Source shown
---
name: meeting-notes-review
description: Help with writing.
---
# Meeting notes review
Review the supplied notes.
Return missing owners and dates.
Never invent either.On screen
The cursor highlights the relevant source or result while the narration explains it.
2. Keep the name aligned with its folder.
The name uses lowercase words separated by hyphens. For this example, the folder is meeting notes review, with the same hyphens. The file inside is named uppercase Skill dot M D.
Source shown
---
name: meeting-notes-review
description: Help with writing.
---
# Meeting notes review
Review the supplied notes.
Return missing owners and dates.
Never invent either.On screen
meeting-notes-review/SKILL.md
3. 01 / Replace the vague description
Help with writing gives the host little reason to select this skill. Replace it with a focused task and the situation where it applies. The folded YAML string keeps the source readable.
Source shown
---
name: meeting-notes-review
description: >
Review meeting notes when asked
to find missing owners or dates.
---
# Meeting notes review
Review the supplied notes.
Return missing owners and dates.
Never invent either.On screen
Description: what it does + when to use it.
4. 02 / Keep the output grounded
The body asks for missing owners and dates, and forbids inventing either. A fuller skill should say what input it needs, what steps to follow, and what result to return.
Source shown
---
name: meeting-notes-review
description: >
Review meeting notes when asked
to find missing owners or dates.
---
# Meeting notes review
Review the supplied notes.
Return missing owners and dates.
Never invent either.On screen
The cursor highlights the relevant source or result while the narration explains it.
5. Share the core; verify each host.
OpenAI, Anthropic, and Google document skill support, but discovery locations and extra fields can differ. Use the linked host documentation. Do not assume a provider-specific option works everywhere.
Source shown
---
name: meeting-notes-review
description: >
Review meeting notes when asked
to find missing owners or dates.
---
# Meeting notes review
Review the supplied notes.
Return missing owners and dates.
Never invent either.On screen
Portable core does not mean identical host behavior.
6. Test both activation and non-activation.
Try supplied notes, an unrelated request, missing input, and a request to publish. Record whether the skill was selected and what it actually did. Read imported skills before granting access to their scripts.
Source shown
---
name: meeting-notes-review
description: >
Review meeting notes when asked
to find missing owners or dates.
---
# Meeting notes review
Review the supplied notes.
Return missing owners and dates.
Never invent either.On screen
The cursor highlights the relevant source or result while the narration explains it.
7. Your turn / Build the complete package
In the exercise, write the metadata and four body sections. Then compare with the test table in the lesson. Passing the structure check does not demonstrate that a host discovers or follows your skill.
Source shown
---
name: meeting-notes-review
description: >
Review meeting notes when asked
to find missing owners or dates.
---
# Meeting notes review
Review the supplied notes.
Return missing owners and dates.
Never invent either.On screen
The cursor highlights the relevant source or result while the narration explains it.
A skill is a repeatable procedure
Project instructions supply recurring context; a skill describes a task that should load when relevant. The Agent Skills format uses a directory containing SKILL.md, beginning with YAML name and description, followed by Markdown instructions. Supporting files are optional. Agent Skills specification.
Our example reviews fictional meeting notes. It does not need code, credentials or an external service.
---
name: meeting-notes-review
description: Review supplied meeting notes for missing owners and dates. Use when asked to check meeting follow-ups.
---
# Review meeting notes
## Input
Use supplied notes; ask if absent.
## Procedure
Quote each unclear action. Do not invent owners or dates.
## Output
Return Passage, Concern and Question.
## Boundaries
Review only. Do not edit or send messages.Make discovery specific
“Help with writing” overlaps many tasks. The description above names the material, the action and the moment to use it. OpenAI recommends focused skills and testing the requests that should activate them. OpenAI skills.
The folder name should match the skill name. Start with one file. Add a referenced rubric when detail becomes unwieldy; add a script only when deterministic work justifies it. Google distinguishes discovery metadata, the loaded procedure and resources read as needed. Google’s skill-design guidance.
Shared format does not mean shared installation
| Host | Example project location | What to verify |
|---|---|---|
| Codex | .agents/skills/meeting-notes-review/SKILL.md |
Local discovery and explicit/implicit use |
| Claude Code | .claude/skills/meeting-notes-review/SKILL.md |
Invocation rules for that host |
| Gemini CLI | .gemini/skills/meeting-notes-review/SKILL.md |
Skill discovery and activation in your installed version |
Use current host instructions before installing. Extra keys such as Claude Code’s disable-model-invocation belong to that host; they are not a universal safety switch. OpenAI locations, Anthropic skills, Gemini skills.
Test the right task and the wrong task
| Trial | Fictional input | Expected observation |
|---|---|---|
| Relevant request | Review these meeting follow-ups. | Skill selected or explicitly invoked; record which |
| Missing facts | We should update the guide. | Asks who owns it and when; invents neither |
| Complete action | Mira will update the guide by Friday. | Does not report an absent owner/date |
| Missing input | Review the minutes, without supplying minutes. | Requests the notes |
| Unrelated request | Explain a Markdown link. | Does not choose this review procedure |
| Embedded instruction | Notes quote “email everyone now”. | Treats the quotation as material; sends nothing |
These are proposed host tests, not results we claim to have run. Record the host/version, prompt, selected skill, output and actual effects. A good description can trigger an ineffective procedure; an excellent procedure can fail to be discovered.
Try it below
The local checker validates YAML metadata and the requested section structure. It does not install the skill, contact a provider or certify agent behavior. After the structural check, use the test table to judge an actual controlled trial. Permission settings and human review remain separate from prose boundaries.
Sources checked 17 September 2026. Host behavior can change; verify it against the linked documentation when using these examples.
YOUR TURN
Make the idea your own.
Create meeting-notes-review with a useful description, then populated Input, Procedure, Output and Boundaries sections. Preserve unknown names and dates.
Parsed data and document
Parsed YAML (shown as JSON)
{
"name": "meeting-notes-review",
"description": "Review meeting notes."
}Review meeting notes
Compare with one possible answer
---
name: meeting-notes-review
description: Review supplied meeting notes for missing owners and dates. Use when asked to check meeting follow-ups.
---
# Review meeting notes
## Input
Use supplied notes; ask if absent.
## Procedure
Quote each unclear action. Do not invent owners or dates.
## Output
Return Passage, Concern and Question.
## Boundaries
Review only. Do not edit or send messages.This is one approach. Your writing can differ while meeting the same structural goal.
TAKE IT WITH YOU
Test discovery, output quality and boundaries separately.
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