15-skills

Skills and the AgentSkills Plugin

This tutorial shows how to use skills to keep agent instructions modular and context-window lean. Instead of a single monolithic system prompt, skills are SKILL.md files loaded on demand when the agent decides they are relevant.

Tutorial Details

Information	Details
Strands Features	AgentSkills plugin, Skill dataclass, @tool decorator
Agent Pattern	Single agent with skill-based instruction routing
Tools	Custom mock tools, file_read from strands-agents-tools
Model	Amazon Nova Lite on Amazon Bedrock

How It Works

1. Skills are stored as SKILL.md files in subdirectories under skills/
2. AgentSkills scans the directory and injects a compact <available_skills> summary into the system prompt
3. When a user message matches a skill's domain, the agent calls the built-in skills tool to load the full instructions
4. The skill can reference additional files (e.g. checklists, escalation guides) via file_read

Prerequisites

• Python 3.10 or later
• AWS account with Amazon Bedrock access configured
• Basic familiarity with Strands Agents — see 01-first-agent if needed

Tutorial Structure

15-skills/
├── README.md
├── requirements.txt
├── agent-skills.ipynb
└── skills/
    ├── returns-policy/
    │   ├── SKILL.md
    │   └── references/
    │       └── returns-checklist.md
    └── technical-troubleshooting/
        ├── SKILL.md
        └── references/
            └── escalation-guide.md

File	Description
agent-skills.ipynb	Step-by-step notebook covering skill creation, plugin setup, and runtime skill injection

What You'll Learn

• SKILL.md structure: front-matter (name, description, allowed-tools) + instruction body
• AgentSkills plugin: how it scans a directory, injects a skill summary, and loads full instructions on demand
• Reference files: how skills use file_read to load supporting documents at activation time
• Programmatic skills: creating a Skill(...) object at runtime without touching the filesystem
• Runtime updates: using set_available_skills to add or replace skills mid-session

Installation

Install the required dependencies:

pip install -r requirements.txt

Then open agent-skills.ipynb from the 15-skills/ directory so that relative paths to ./skills/ resolve correctly.

Related Tutorials

• 02-tools-and-mcp — building the tools that skills rely on
• 06-memory — combining skills with persistent memory
• 13-human-in-the-loop — hooks and agent lifecycle events