Claude Skills: A Guide to AI-Powered Skills

Skills turn Claude from a general-purpose AI into a specialist that knows your workflows, your tools, and your standards. This guide covers everything — what Claude Skills are, how they work, how to build your own, and how to use them across Claude.ai, Claude Code, and the API.

What Are Claude Skills?

Claude Skills are folders of instructions, scripts, and resources that Claude loads dynamically to perform better at specific tasks. Think of them as onboarding materials for an AI — they teach Claude how to do something in a repeatable, consistent way.

Skills were introduced by Anthropic in October 2025 and have since become a core part of how developers and teams customize Claude's behavior. In December 2025, Anthropic published Agent Skills as an open standard for cross-platform portability.

Key concepts:

Why Skills matter:

Composable — Skills stack together. Claude automatically identifies which skills are needed and coordinates their use
Portable — Same format everywhere. Build once, use across Claude.ai, Claude Code, and API
Efficient — Only loads what's needed, when it's needed. A skill description takes just a few dozen tokens; full content loads on demand
Powerful — Skills can include executable code for tasks where traditional programming is more reliable than token generation

How Claude Skills Work Under the Hood

Skills operate through a pattern called progressive disclosure. Here's the lifecycle:

Step 1: Discovery When a session starts, Claude scans all available skills and reads the frontmatter metadata (name + description) from each SKILL.md file. This costs only a few tokens per skill.

Step 2: Matching When you make a request, Claude evaluates whether any available skill is relevant. If you ask Claude to create a PowerPoint, it matches to the PPTX skill. If you ask a general question, no skill is loaded.

Step 3: Loading Claude loads the full SKILL.md instructions and any associated resources (scripts, templates, reference files) into its context. This gives Claude detailed, step-by-step guidance for the task.

Step 4: Execution Claude follows the skill instructions to complete the task — running scripts, applying templates, and producing outputs according to the skill's guidelines.

Skill file structure:

Plain Text

my-skill/ ├── SKILL.md # Instructions + YAML frontmatter (required) ├── scripts/ # Optional executable scripts ├── templates/ # Optional templates or reference files └── resources/ # Optional additional assets

SKILL.md format:

yaml

YAML

--- name: my-skill-name description: A clear description of what this skill does and when to use it --- # My Skill Name ## Instructions [Step-by-step guidance for Claude] ## Examples [Concrete examples of using this skill] ## Guidelines [Best practices and constraints]

Types of Claude Skills

Claude Skills fall into three categories — each serves a different purpose.

Anthropic Pre-Built Skills

Created and maintained by Anthropic. Available to all users. Claude invokes them automatically when relevant.

Partner Skills

Skills that may be distributed through partner or directory ecosystems, depending on platform availability and current official support.

Custom Skills

Built by you or your team. Package your organization's workflows, brand guidelines, domain expertise, and institutional knowledge into reusable skills that Claude follows consistently.

Examples of custom skills:

Generate PRDs following your company's template
Write changelog summaries in your brand voice
Analyze data using your organization's specific methodology
Create customer-facing documents with your design standards
Automate code review workflows with your team's conventions

How to Build Your Own Claude Skills

Creating a custom skill is straightforward — no coding required for simple skills, though you can add executable scripts for advanced functionality.

Step 1: Create the SKILL.md File Write a Markdown file with YAML frontmatter containing the name and description, followed by clear instructions, examples, and guidelines.

Step 2: Add Resources (Optional) Include scripts, templates, or reference files alongside your SKILL.md. Claude can execute scripts and reference these files when the skill is active.

Step 3: Install the Skill

Step 4: Test and Iterate Ask Claude to perform the task your skill covers. Review the output, refine instructions, add more examples, and tighten guidelines until the results are consistent.

Best practices:

Keep the description specific — include both what the skill does and when Claude should use it
Use concrete examples, not abstract instructions
Scope each skill to one clear task area
Test with varied prompts to ensure robustness
Use the Skill Creator tool for guided creation

How Teams Use Claude Skills with Verdent

Verdent's multi-agent architecture makes Skills even more powerful. Run multiple skill-powered tasks in parallel, across isolated workspaces, with planning and review built in.

Concept	Explanation
What a Skill is	A directory containing a SKILL.md file with YAML frontmatter and Markdown instructions, optionally accompanied by scripts and templates
How Claude finds them	At the start of a session, Claude scans available skills, reads the short description from each SKILL.md frontmatter, and loads the full skill only when relevant — keeping token usage efficient
Where they work	Claude.ai, Claude Code, Claude Agent SDK, and the Messages API — build once, use everywhere
Who can use them	Available to Pro, Max, Team, and Enterprise users on Claude.ai. Also available via Claude Code and the API with Code Execution Tool

Skill	What It Does
PPTX (PowerPoint)	Create and edit professional presentations with layouts, charts, and formatting
XLSX (Excel)	Generate spreadsheets with formulas, charts, and structured data
DOCX (Word)	Produce formatted documents with headings, tables, and page numbers
PDF	Read, fill, merge, and create PDF files including form filling

Platform	How to Install
Claude.ai	Upload via Settings → Skills
Claude Code	Add to ~/.claude/skills/ (personal) or .claude/skills/ (project). Can also install via plugins from the anthropics/skills marketplace
Claude API	Use the /v1/skills endpoint for programmatic skill management and versioning

Use Case	What the Team Does	Skills Involved
Enterprise Document Generation	Generate branded presentations, reports, and spreadsheets that follow company standards — consistently, at scale	PPTX, DOCX, XLSX + custom brand guidelines skill
Automated Code Review	Every PR gets reviewed against the team's coding conventions, style guide, and security checklist	Custom code review skill + Verdent parallel agents
PRD & Spec Writing	Product managers describe a feature in plain language → Claude produces a full PRD in the team's template	Custom PRD template skill
Customer Onboarding Docs	Generate personalized onboarding materials for each new customer based on their plan and industry	Custom onboarding skill + DOCX/PDF skills
Data Analysis Pipelines	Analysts describe what they need → Claude runs the analysis following the organization's methodology and formatting standards	Custom data analysis skill + XLSX skill
Changelog & Release Notes	Every release, Claude generates formatted changelogs from commit history in the team's voice	Custom changelog skill via Claude Code

Frequently Asked Questions

What are Claude Skills?

Claude Skills are folders of instructions, scripts, and resources that Claude loads dynamically to improve performance on specialized tasks. They teach Claude how to complete specific tasks in a repeatable way — from creating documents to following your organization's workflows.

Do I need to code to create a skill?

No. Simple skills only require a Markdown file with instructions. For more advanced functionality, you can optionally include executable scripts, but the core format is just structured text.

Where can I use Claude Skills?

Skills work across Claude.ai, Claude Code, the Claude Agent SDK, and the Messages API. Build once, use everywhere. Anthropic has also published Agent Skills as an open standard, meaning the format works across platforms that adopt it.

How do Skills relate to MCP (Model Context Protocol)?

They're complementary. MCP connects Claude to external services and data sources. Skills teach Claude how to use those tools effectively. You can use both together — MCP provides the tools, Skills provide the procedures.

How does Verdent work with Claude Skills?

Verdent's multi-agent architecture lets you run multiple skill-powered tasks in parallel across isolated workspaces. You can install skills via Claude Code plugins, share them through version control, and orchestrate complex workflows that combine multiple skills — all with Verdent's planning, review, and diff capabilities.