Write a description that triggers at the right moment

Lesson objective

By the end of this lesson, you will be able to write a skill's name and description so that it triggers on the right requests and not on others, and choose who can invoke it (Claude, you, or both).

Topics covered

• skill description
• skill triggering
• Claude Skills
• invocation
• SKILL.md

Where it fits

Design and write your skill

How do I write a skill that triggers at the right moment, produces a checkable result and has only the permissions it needs?

Lessons in this module

1. Write a description that triggers at the right moment (this lesson)
2. Scope your skill before writing it
3. Write the SKILL.md and install it
4. A skill's tools and permissions

What you will learn in the course

This lesson is part of the course Build reliable Claude Skills for your product work

• Identify a recurring task that justifies a skill rather than a one-off prompt, and explain how the skill is loaded (progressive disclosure).
• Choose and justify the right mechanism for a given need (skill, CLAUDE.md, subagent, MCP server, hook).
• Write a name and description that trigger the skill at the right moment, and choose who can invoke it.
• Design a complete SKILL.md (frontmatter, checkable rules, procedure, output format, reference files) from a scoping brief.
• Configure a skill's pre-approved and removed tools according to risk, without confusing pre-approval with restriction.
• Test a skill's triggering and output with evaluation scenarios, iterate, then measure its value over time.
• Choose, audit and share skills (third-party or internal) while managing the security risks.

Related courses

• Choosing and using AI tools at workAll levels · ~1 hr 40 min
• Prompting for product managers: delegate, describe, verifyJunior · ~2 hr 45 min
• Understand what LLMs do well, and where they failAll levels · ~2 hr