Custom skills

Create an Agent Skill from a task you already repeat.

Use one real prompt, one expected result, and clear completion checks. Once that process works, move the repeated instructions and tools into a skill.

Choose one job

Write down the request, inputs, output, and stop conditions.

Define the trigger

Describe the exact tasks that should load the skill.

Move repeated work into files

Use scripts for deterministic checks and references for project rules.

Test failure cases

Confirm the skill stops when evidence, permission, or required input is missing.

Frontmatter

Make the description do the routing.

The agent sees the name and description before it loads the instructions. State what the skill does and the situations that should trigger it. Put the procedure in the body.

---
name: verify-public-business-data
description: Check imported business records against approved public sources and route uncertain evidence to review. Use when a lead record is created, refreshed, or approved for a proposal.
---

Package

Keep SKILL.md short.

Put the core sequence in SKILL.md. Move detailed policy into references and repeated code into scripts. Add assets only when the output needs a template, icon, or source file.

verify-public-business-data/
├── SKILL.md
├── scripts/
│   └── check-source-urls.py
└── references/
    └── approval-rules.md

Anonymized production examples

Four tasks worth packaging as skills

These examples are adapted from a private lead-research and website-production system. Company names, customers, domains, credentials, and internal thresholds have been removed.

verify-public-business-data

Check imported records and public website evidence before a lead enters the approved queue.

Package: SKILL.md + approval rules + a deterministic URL checker
Failure test: A record with a missing source must be sent to review, never silently approved.

review-preview-site

Render a generated site at four viewports and check layout, links, claims, and contact details.

Package: SKILL.md + browser script + screenshot checklist
Failure test: The run fails when a page invents a service, price, testimonial, or booking date.

assemble-proposal-package

Create a preview, proposal, and outreach draft only after the required approval record exists.

Package: SKILL.md + templates + output schema
Failure test: The skill creates drafts and artifacts; it cannot send messages or bypass approval.

run-release-gate

Run tests, migrations, secret checks, browser QA, and rollback checks before release.

Package: SKILL.md + preflight script + deployment reference
Failure test: A failed migration check stops the release and keeps the failure log.

Test the trigger and the stop conditions.

Run a prompt that should trigger the skill and one that should not.

Remove a required input and confirm the skill asks for it or stops.

Run the same task without the skill and compare the result.

Re-run the tests after changing scripts, dependencies, or permissions.

Find a skill-creation package to inspect.

Search skill creators