Courses/Introduction to Agent Skills/Wiring Skills into Subagents
Scope, Sharing and DistributionLesson 13 of 16

Wiring Skills into Subagents

The Surprise: Subagents Don't See Your Skills

Here's something that surprises people: subagents don't automatically see your skills. When you delegate a task to a subagent, it starts with a fresh, clean context — and that context does not include the skills available in your main conversation. If you want a subagent to apply a skill, you have to wire it in explicitly.

Two key distinctions

Built-in agents (Explore, Plan) can't access skills at all. Custom subagents CAN use skills — but only the ones you explicitly list. And skills are loaded when the subagent STARTS, not on demand like in the main conversation.

The skills: Frontmatter Field

To give a custom subagent skills, list them in the skills: field of its agent markdown file (in .claude/agents/). The full content of each listed skill is preloaded into the subagent's context at startup — so the subagent carries that expertise into every task it handles.

markdownThe skills: field preloads accessibility-audit and performance-check into this subagent at startup.
---
name: frontend-reviewer
description: Reviews frontend code for accessibility and performance.
tools: Bash, Glob, Grep, Read, Skill
model: sonnet
skills: accessibility-audit, performance-check
---

You are a frontend code reviewer. Apply the preloaded skills to every review.
ℹ️

Preloaded, not matched

Note the difference from the main conversation: in your main thread, a skill loads when its description matches your request. In a subagent, the skills listed in the skills: field are preloaded in full at startup — there's no matching step. First make sure those skills exist in .claude/skills/.

Two Directions, One Mental Model

Recall from the advanced section that skills and subagents combine two ways. This lesson is the second direction (subagent carries skills); the first (skill runs as a subagent via context: fork) we covered earlier. Keeping them straight prevents confusion:

ApproachSystem promptTaskSkill role
Skill with context: forkFrom the agent typeThe SKILL.md contentThe skill IS the task
Subagent with skills: fieldThe subagent's bodyClaude's delegation messageThe skills are REFERENCE knowledge

context: fork → a skill runs as a subagent. skills: field → a subagent carries skills as reference. Different directions, complementary.

When to Wire Skills into Subagents

This pattern shines when you want isolated, expert task delegation with consistent standards baked in — rather than relying on prompts to remind a subagent of your conventions each time.

  • You want isolated task delegation with specific expertise (a reviewer that always applies your standards).
  • Different subagents need different skills (a frontend reviewer vs a backend reviewer).
  • You want to enforce standards in delegated work without depending on prompt wording.
  • Workflow: create the skills in .claude/skills/, then add the skills: field to a new or existing agent in .claude/agents/.

Section complete

You can now scope, share, and delegate skills. The final section is about operating skills day-to-day: troubleshooting, best practices, and a course wrap-up.

Key Takeaways

  • Subagents do NOT automatically see your skills — delegated work starts with a fresh context that excludes them.
  • Built-in agents (Explore, Plan) can't access skills at all; only custom subagents can, and only the ones you explicitly list.
  • List skills in a custom subagent's skills: frontmatter field (in .claude/agents/); their full content is preloaded at startup.
  • Subagent skills are PRELOADED (no matching step), unlike the main conversation where a skill loads when its description matches.
  • Two directions: a skill with context: fork runs AS a subagent (skill = task); a subagent's skills: field carries skills as REFERENCE.
  • Use this for isolated expert delegation with baked-in standards (e.g. distinct frontend vs backend reviewers) — create the skills first, then add the skills: field.

Check Your Understanding

Test what you learned in this lesson.

Q1.Do subagents automatically have access to the skills in your main conversation?

Q2.How are skills loaded into a custom subagent that lists them?

Q3.What's the difference between a skill using context: fork and a subagent using the skills: field?

Q4.When is wiring skills into a custom subagent most useful?

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