Advanced Automation: Mastering Skills & Sub-Agents in Claude Cowork

If you're using Claude Cowork like a chatbot, you're using 10% of its power. The true potential unlocks when you start composing workflows using Skills and Sub-Agents.

The Composition Model

Think of automation as building with lego blocks:

  • Skills: The "Instructions". Reusable prompt templates (e.g., "How we format code").
  • Sub-Agents: The "Workers". Parallel instances of Claude that do the work.
  • Main Agent: The "Manager". Coordinates the workers and synthesizes the result.

1. Mastering Skills

A Skill is just a persistent set of instructions. Instead of typing "Please format this as a table..." every time, you save a skill-table-format.md file.

Example: The "Code Review" Skill

Create a file skills/code-review.md:

# Code Review Standards
1. Security: Check for OWASP Top 10 vulnerabilities.
2. Performance: Flag any O(n^2) loops.
3. Style: Enforce TypeScript strict mode.
4. Output: detailed list of issues with line numbers.

Usage: "Review src/auth.ts using the code-review skill."

2. Unleashing Sub-Agents

Sub-Agents allow parallel execution. This is the game changer for speed.

The "Research Team" Pattern

Instead of: "Research these 5 competitors and write a report" (Serial, slow).

Do this: "Spawn 5 sub-agents. Assign each one to research ONE competitor deeply. Once all 5 report back, synthesize their findings into a comparison matrix."

Why it's better:

  1. Speed: 5 agents work at the same time.
  2. Focus: Each agent has a clean context window, focused only on one company.
  3. Quality: Less "hallucination" because context isn't overloaded.

3. From Prototype to Script

The ultimate optimization loop (credit: John Lindquist):

  1. Prototype: Run a task manually with sub-agents. It works, but it's slow and costs tokens.
  2. Analyze: Ask Claude: "Look at how we just did this task. Write a Python/Node script to automate the mechanical parts."
  3. Harden: Save that script. Now your "Research Skill" just runs the script first, then uses AI only for the final synthesis.

Result: A workflow that is 10x faster and 10x cheaper.

Need a deep dive on how Skills work under the hood? Read our technical guide on Mastering the Skills System to learn about SKILL.md architecture and built-in capabilities.