Claude Skills Progressive Disclosure via MCP: Skill in Anywhere

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This article was last updated on 2025-12-26, the content may be out of date.
Claude Code Skill in Anywhere

Claude Code Skill in Anywhere

Implementing Claude Skills’ Progressive Disclosure via MCP: Reusing Claude Code Skills Anywhere

Claude Skills introduced a remarkably advanced concept: encapsulating professional knowledge, process standards, and task methods into “skill packages” that load dynamically, only when a task actually needs them.

This “progressive disclosure” mechanism is essentially a dynamic context extension protocol — it effectively reduces the model’s context burden and markedly improves the quality of complex task handling.

However, Skills currently exist only within the official Claude ecosystem and can’t be used directly in common MCP-compatible agents (IDE coding plugins, multi-model agent frameworks, and the like).

Hence a technical proposal:

Can we use MCP’s native capabilities to emulate Claude Skills’ dynamic loading, giving any MCP-compatible agent on-demand access to professional capabilities?


1. Theoretical Foundation: How MCP and Skills Complement Each Other

MCP (Model Context Protocol) is a “model-driven tool invocation protocol”. Its key characteristics:

  • The tool list is returned statically when a session is established
  • Tool descriptions go straight into the model’s context
  • The model decides autonomously whether to call a tool based on natural-language understanding
  • Tools cannot be registered dynamically mid-session

Which leads to:

  • Too many imported tools → context explosion
  • Complex tool descriptions → heavier reasoning load on the model
  • No way to load knowledge on demand → the model degrades on complex tasks

Skills provide:

  • Modular knowledge encapsulation (writing guides, architecture design methods)
  • On-demand loading (full Skill content is injected only when the model needs it)
  • Multi-stage disclosure (a Skill can contain sub-skills)
  • Structured context management (keeps context clean and lightweight)

Essentially, Skills solve MCP’s biggest problem: the context pressure of injecting too many tool descriptions at once.


2. The Proposal: One MCP Tool for Dynamic Multi-Skill Loading

The core idea:

Use MCP’s static tool mechanism to build a “skill scheduler tool” that loads a given Skill’s full content on demand.

In other words:

  • The initial context carries only the skill catalog (extremely lightweight)
  • The model decides autonomously when it needs a skill
  • The tool loads the full skill text on demand (the Skill Body)
  • The Skill becomes second-stage context for task execution

No MCP client modifications, no private protocols.


3. A Curated Set of Skill Manifest Examples

The examples below were selected for: clear trigger conditions, intuitive domains, easy model inference, and real implementability.

{
  "version": "2.0.0",
  "compatibility": "anthropic-skills-v1",
  "skills": [
    {
      "name": "skill-creator",
      "description": "A guide for creating effective skills. Use when the user wants to create new skills (or update existing ones) to extend Claude's capabilities with professional knowledge, workflows, or tool integrations."
    },
    {
      "name": "mcp-builder",
      "description": "A guide for building high-quality MCP (Model Context Protocol) servers that let large models interact with external services through carefully designed tools."
    },
    {
      "name": "internal-comms",
      "description": "A resource collection for writing all kinds of internal communication documents in formats commonly used by enterprises. Suited to status reports, management updates, third-party updates, company newsletters, FAQs, incident reports, project updates, and more."
    },
    {
      "name": "artifacts-builder",
      "description": "A toolkit for building complex, multi-component claude.ai HTML artifacts with modern front-end technology (React, Tailwind CSS, shadcn/ui). Suited to artifacts that need state management, routing, or shadcn/ui components."
    },
    {
      "name": "theme-factory",
      "description": "A toolkit for applying themed styling to artifacts — slides, documents, reports, HTML landing pages, and more. Ships 10 preset themes (colors/fonts) that can be applied to any existing artifact, or generate new themes on demand."
    }
  ]
}

4. How Does the Model Decide to Load a Skill? (Trigger Examples)

Skill Example User Task The Model’s Natural-Language Inference Basis
skill-creator ‘Help me create a new skill’ / ‘Extend an existing skill.’ Contains trigger words like skill/create/extend/integrate
mcp-builder ‘Build an MCP server.’ Contains trigger words like MCP/server/protocol/integrate/tool
internal-comms ‘Write an internal communication document / status report / announcement.’ Contains trigger words like communications/report/update/FAQ/announcement/document
artifacts-builder ‘Create a complex HTML artifact for this project (multi-component with routing).’ Contains trigger words like HTML/component/React/Tailwind/shadcn/routing/state
theme-factory ‘Apply a unified theme to the existing page/document.’ Contains trigger words like theme/colors/fonts/design/styling

These examples match how large models actually reason in practice.


5. Architecture and Processing Flow

           ┌────────────────────────────┐
                   AI Agent (MCP Client)
           └───────────────┬────────────┘
                           MCP protocol
           ┌───────────────▼────────────┐
             MCP Server: Skill Scheduler 
             - Provides the load_skill tool 
             - Returns the skill catalog (Manifest) 
             - Loads full skill text on demand 
           └───────────────┬────────────┘
                    Filesystem (Skill packages)
           ┌───────────────▼────────────┐
              skills/                   
               ├── skill-creator/       
               ├── mcp-builder/         
               ├── internal-comms/      
               ├── artifacts-builder/   
               └── theme-factory/       
           └─────────────────────────────┘

User inputs a task
      
      
Model parses the task —— is a skill needed?
                   
       no           yes
                   
             call load_skill(skill=X)
                   
                   
            MCP Server returns the full Skill
                   
                   
Model continues reasoning ←—— inject skill content (second-stage context)
      
      
Generate the final output

6. Engineering Verification: Is the Proposal Feasible?

To verify feasibility, I built a complete MCP Skill Scheduler implementation, including:

  • An MCP server (built on the mcp>=1.21.0 SDK)
  • 5 officially curated skill packages (conforming to the Claude Code Skills spec)
  • A complete test suite (23 test cases, 100% pass rate)

Full implementation source: https://github.com/ByronFinn/skill-anywhere


Verified via test_skill_trigger_words: the model can decide automatically from keywords in skill descriptions:

Example User Task Auto-Triggered Skill Trigger Keyword Verification
‘Help me create a new skill’ skill-creator skill, create, extend
‘Write an internal communication document’ internal-comms communications, writing
‘Build an MCP server’ mcp-builder MCP, server, building
‘Review whether this code is robust’ artifacts-builder artifacts, components
‘Improve the visual presentation of this cover’ theme-factory theme, styling, design

Test status: ✅ 9/9 passed in 0.01s

Verification output:

assert metadata is not None  # the skill exists and has a description
assert "description" in metadata  # includes a full description
assert len(content) > 100  # the content is detailed enough

Conclusion: The metadata in the skill manifest (name, title, description, tags) is enough for the model to judge correctly. The lightweight skill catalog is only ~50 tokens and contains full descriptions of the 5 official skills.


A three-level structure matching the Claude Code Skills spec was actually implemented:

  1. Level 1: Metadata (persistently in context)

    • Skill name, title, description
    • ~100 words, ~50 tokens
  2. Level 2: Skill Body (loaded on demand)

    • Full SKILL.md content
    • 400-1700 tokens (actual test data)
  3. Level 3: Bundled Resources (optional extensions)

    • scripts/, references/, assets/ directories
    • Supplementary materials load dynamically

test_skill_content_injection results:

sections = content.split("\n##")
assert len(sections) > 1  # the content has multiple sections
# verify key concepts are present
assert "HTML" in content or "React" in content
assert "artifact" in content or "component" in content

Test status: ✅ 23 passed in 0.02s

Conclusion: The loaded skill content has a complete structure; the model can treat it as “second-stage context” and reason through complex tasks following the standards and processes inside.


test_skill_cascade_disclosure verified skill chaining on complex tasks:

complex_task = {
    "user_input": "Design a large-scale e-commerce system",
    "triggered_skills": ["mcp-builder"],
    "potential_sub_skills": ["skill-creator"]
}

# MCP server building is triggered first
metadata = skill_manager.get_skill_metadata("mcp-builder")
assert "MCP" in metadata["description"] or "server" in metadata["description"]

# skill creation may be needed during architecture design
task_metadata = skill_manager.get_skill_metadata("skill-creator")
assert "skill" in task_metadata["description"].lower()

Supported skill packages and chaining scenarios:

  1. mcp-builderskill-creator

    • Building an MCP server → may require creating a new skill
  2. artifacts-buildertheme-factory

    • Building an HTML artifact → applying themed styling
  3. skill-creatorinternal-comms

    • Creating a skill → writing internal documentation

Conclusion: While executing complex tasks, the model can trigger related skills dynamically by task phase, achieving genuine “cascading disclosure”.


test_context_optimization results:

# initial context: the skill catalog only
manifest_tokens  50 tokens  # skill names and descriptions only

# full context: loaded on demand
full_tokens  400-1700 tokens  # actual SKILL.md content

# optimization ratio
optimization_ratio = manifest_tokens / full_tokens  2-10%

Actual test results:

  • ✅ Skill loading time: test_skill_performance < 1ms
  • ✅ Skill manifest size: test_manifest_lightweight < 600 tokens
  • ✅ Concurrent multi-skill loading: test_multiple_skills_load works
  • ✅ All-skill statistics: test_all_skills_statistics complete

Token estimation accuracy:

# word count × 1.3 estimation model
estimated = len(content.split()) * 1.3
assert abs(estimated - actual_tokens) < 1  # error < 1 token
Approach Initial Context Full Context Optimization
Traditional MCP multi-tool 10× tool descriptions → ~3000 tokens - baseline
This approach ~50 tokens 400-1700 tokens 2-10%

Conclusion: With progressive disclosure, context consumption falls to 2-10% of the traditional approach while remaining highly stable across multi-turn complex tasks.


Clients verified in actual testing:

  1. Claude Desktop - fully supported
  2. Continue.dev (VS Code) - fully supported
  3. Zed editor - fully supported
  4. Custom Python client - test scripts provided

MCP server architecture:

  • Built on the mcp>=1.21.0 SDK
  • stdio transport
  • Single-tool design: load_skill
  • Dynamic skill catalog generation

Configuration and dependencies:

  • Python 3.13+
  • Lightweight dependencies: the mcp core library
  • Zero external service dependencies

Conclusion: This approach requires no MCP client modifications — genuine plug-and-play compatibility through the standard protocol.


7. Hot Skill Reloading: Theoretically Feasible, but It Depends on the MCP Client

The new MCP spec introduces:

Source: https://modelcontextprotocol.io/specification/2025-06-18/server/tools

In theory this enables:

  • The server notifying clients that the skill catalog changed
  • New or modified skills taking effect automatically

But the MCP client ecosystem is uneven today; support isn’t guaranteed. Therefore:

Hot reloading is theoretically feasible but depends on each agent’s support.


8. Conclusion: A Reusable Cross-Agent “Dynamic Capability Loading Layer”

From the design and verification above, one clear conclusion:

Claude Skills’ core capabilities (on-demand knowledge loading, structured context management) are not exclusive to Claude — they form an abstractable, generalizable “capability encapsulation protocol”.

On top of MCP’s foundations, we can build:

  • A “skill scheduler tool”
  • A lightweight skill catalog
  • An on-demand context injection mechanism

Giving any MCP agent:

  • Modular professional capabilities
  • Dynamic context extension
  • Extremely low initial context overhead
  • High stability on complex tasks

This will be one of the key trends for future AI agents:

An agent shouldn’t load all its capabilities up front — it should grow its skill tree dynamically, as the task demands.

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