AgentSkill - Progressive MCP client with three-layer lazy loading. Validates AgentSkills.io pattern for efficient token usage.
MCP Progressive AgentSkill
AgentSkill for MCP - Three-layer progressive disclosure validates AgentSkills.io pattern for efficient MCP token usage
Design Intent
Proven AgentSkills Pattern
In the AgentSkills.io ecosystem, Progressive Disclosure combined with Script linkage has been validated as effective:
- AI only loads specific information when needed, significantly reducing token usage
- Scripts can be invoked via AI commands, providing high customization potential
- Sharing tools via scripts is far less costly than developing and using complex MCP Servers
The impact of this pattern is significant and substantial.
Current MCP Skill Dilemma
Despite this, many Skills using MCP still face two extreme options:
Option 1: Install MCP directly in Claude Code, Skill only guides AI to call MCP
- MCP server occupies AI context long-term
- Full tool list loaded every conversation
- Token waste, and MCP itself cannot be progressively explored
Option 2: Write custom scripts yourself
- Tests user's programming skills
- High customization but lacks standards
- Each MCP has its own format/specs, high adaptation cost for both open and closed source
- Difficult to maintain and share
This Skill's Goal
Validate whether AgentSkills.io pattern applies to improving MCP usage
This concept validation attempts to port AgentSkills' successful pattern to the MCP domain:
- Can AgentSkills architecture apply to MCP server management?
- Is three-layer progressive disclosure effective in MCP scenarios?
- Is Python scripts + Simple MCP Client architecture more practical than direct MCP usage?
Experimental Nature
This is not a mature product, but an experiment:
- Test AgentSkills pattern applicability in MCP domain
- Explore actual effectiveness of three-layer loading
- Validate pros/cons of Daemon architecture
- Serve as reference prototype for future development
Important Disclaimer
This is a very early, rushed AI-assisted demo version with current goals:
- Validate concept feasibility
- Explore usage patterns
- Collect feedback for improvements
Not recommended for production use. Expect many issues and optimization opportunities. If you find any problems or have suggestions, please open an Issue or contribute a PR.
Core Concepts
Three-Layer Progressive Disclosure
Like AgentSkills, you don't need to load everything at once:
Layer 1: Know which servers are available
Load only basic info (name, version, status)
Usage: ~50-100 tokens
Use case: Check availability, choose server
Layer 2: Know what tools this server provides
Load tool list (names + brief descriptions)
Usage: ~200-400 tokens
Use case: Browse available tools, decide what to use
Layer 3: Load only the tools you need
Load complete input format for specific tool
Usage: ~300-500 tokens/tool
Use case: Before calling tool
Why This Approach
Assume an MCP server has 20 tools, you only need 2:
| Loading Method | Token Usage | Description | |:---|:---:|:---| | Load All | 6,000 | 20 tools × 300 tokens | | Three-Layer Progressive | 850 | Metadata(50) + List(200) + 2 tools(600) | | Savings | 86% | Only load what you need |
Development Status
Future Plans
Based on concept validation results, future directions include:
Short-term Goals
- More convenient MCP Servers management (UI, auto-discovery, one-click install)
- Implement Auth features (API Key management, permission control)
Mid-term Goals
- Enhance MCP Server tool calling experience (better error messages, parameter validation, result formatting)
- Intercept MCP Server output with customizable Script data processing, avoid massive messy data entering conversation memory
This project's direction depends on:
- Concept validation results
- Community feedback
- Actual usage needs
Feedback and suggestions welcome.
Quick Start
Prerequisites
- Node.js >= 18.0.0
- Python >= 3.8
- npm
1. Install
python scripts/setup.py
This command automatically checks environment, installs dependencies, and compiles the daemon.
2. Configure
Edit mcp-servers.json:
{
"servers": {
"playwright": {
"transportType": "stdio",
"command": "npx",
"args": ["@playwright/mcp@latest", "--isolated"]
}
}
}
3. Start Daemon
python scripts/daemon_start.py --no-follow
4. Test Connection
# Layer 1: Check server status
python scripts/mcp_metadata.py --server playwright
# Layer 2: List available tools
python scripts/mcp_list_tools.py --server playwright
# Layer 3: View specific tool format
python scripts/mcp_tool_schema.py --server playwright --tool browser_navigate
5. Call Tool
python scripts/mcp_call.py \
--server playwright \
--tool browser_navigate \
--params '{"url": "https://example.com"}'
Usage Examples
Web Automation
Automate browser operations using Playwright MCP server:
# 1. Navigate to website
python scripts/mcp_call.py \
--server playwright \
--tool browser_navigate \
--params '{"url": "https://www.apple.com/tw"}'
# 2. Take screenshot
python scripts/mcp_call.py \
--server playwright \
--tool browser_take_screenshot
# 3. Click element
python scripts/mcp_call.py \
--server playwright \
--tool browser_click \
--params '{"element": "Mac link", "ref": "e19"}'
Multi-Tool Batch Execution
Create session.json to execute a series of operations:
[
{
"tool": "browser_navigate",
"params": {"url": "https://example.com"},
"desc": "Navigate to example.com"
},
{
"tool": "browser_take_screenshot",
"params": {},
"desc": "Take screenshot"
},
{
"tool": "browser_click",
"params": {"element": "Submit", "ref": "e42"},
"desc": "Click submit button"
}
]
Execute:
python scripts/mcp_session.py --server playwright --script session.json
Hot Reload Configuration
Reload after modifying mcp-servers.json without restarting daemon:
python scripts/daemon_reload.py
Response example:
{
"success": true,
"reloaded": true,
"oldServers": ["playwright_global"],
"newServers": ["playwright_global", "filesystem_global"],
"servers": ["playwright", "filesystem"]
}
Architecture
System Architecture
+-----------------------------+
| AI / Skill Layer |
| (Python scripts call API) |
| - mcp_metadata.py |
| - mcp_list_tools.py |
| - mcp_call.py |
+-----------+-----------------+
| HTTP (13579)
v
+-----------------------------+
| MCP Daemon (Long-Running) |
| - Maintain persistent MCP |
| connections |
| - Provide HTTP API |
| - Manage shared sessions |
| - Support Hot Reload |
+-----------+-----------------+
| MCP Protocol
v
+-----------------------------+
| MCP Servers |
| - playwright (browser) |
| - filesystem (files) |
| - github (Git) |
| - custom servers |
+-----------------------------+
Session Management
| Session Type | Purpose | Lifecycle | |:---|:---|:---| | Global Session | Pre-connected, shared by all requests | Daemon start → shutdown | | Dynamic Session | Independent connection, specific use | On-demand → manual close |
Configuration
Environment Variables
| Variable | Default | Description |
|:---|:---:|:---|
| MCP_DAEMON_PORT | 13579 | Daemon HTTP port |
Transport Types
| Type | Description | Use Case |
|:---|:---|:---|
| stdio | Standard input/output | Local MCP server (default) |
| http-streamable | HTTP streaming | Remote MCP server |
| sse | Server-Sent Events | Event-driven MCP server |
MCP Servers Configuration
Edit mcp-servers.json:
{
"servers": {
"playwright": {
"transportType": "stdio",
"command": "npx",
"args": ["@playwright/mcp@latest", "--isolated"]
}
}
}
Resources
- SKILL.md - Complete usage guide
- MCP Specification
- MCP TypeScript SDK
- AgentSkills.io
This is a concept validation project, feedback welcome