Key points
- Project commands live in .claude/commands/ and are shared through version control; personal ones live in ~/.claude/commands/.
- Skills live in .claude/skills/, one folder each with a SKILL.md whose frontmatter supports context: fork, allowed-tools and argument-hint.
- context: fork runs the skill in an isolated sub-agent so verbose or exploratory output stays out of the main conversation.
- allowed-tools restricts which tools the skill may call, which is enforced by Claude Code rather than suggested in prose.
- argument-hint prompts the developer for required parameters when the skill is invoked without them.
- Personal variants of a team skill go in ~/.claude/skills/ under a different name so teammates are unaffected.
- Skills are on-demand; CLAUDE.md is always loaded. Universal standards go in CLAUDE.md, task-specific workflows go in skills.
Skills the exam expects
- Create a project-scoped command that every developer gets on clone.
- Apply context: fork to skills that produce a lot of output, such as codebase analysis or brainstorming.
- Use allowed-tools to make destructive actions impossible during a skill, for example blocking file writes.
- Add argument-hint so developers are prompted for required inputs.
- Decide between a skill and a CLAUDE.md entry based on whether the guidance is always needed.
Common misconceptions
- "Putting a workflow in CLAUDE.md makes it available as a command." CLAUDE.md is guidance, not an invocable command.
- "A warning in the skill text stops Claude from deleting files." Only allowed-tools enforces that.
- "context: fork changes what the skill is allowed to do." It changes where the output goes, not permissions.
Watch for
- Team commands sitting in a home directory where nobody else can see them.
- Editing the shared skill to satisfy one person's preference.
- Verbose skills running in the main context and crowding out the actual task.
Practice task 3.2
56 practice items cover this task in CCA Prep Studio: flashcards, matching, scenario questions and explain-it-back exercises, each tracked toward your mastery score.