What is MCP? The Complete Guide to Model Context Protocol

What is Model Context Protocol?

Model Context Protocol (MCP) is an open standard created by Anthropic in November 2024 that lets AI agents connect to external data sources and tools in a uniform, secure way. Think of MCP as USB for AI agents: just as USB lets you connect any device to any computer, MCP lets you connect any data source to any AI agent.

Instead of copying and pasting data into the chat, an MCP server exposes APIs as structured tools that the agent can call directly. For example, an MCP server for weather data lets the agent pull a live forecast from IMS (Israel Meteorological Service) without you having to browse the website yourself.

Why MCP Changes the Game

Before MCP, every AI agent was trapped inside its chat window. If you wanted the agent to work with external data, you had to copy and paste manually, or build a custom integration for each agent separately.

Before MCP:

The AI agent only receives what you paste into the chat
Every integration requires custom development
No uniform way to connect data sources

After MCP:

The agent accesses data sources directly through MCP servers
One server works with every agent that supports MCP
An open standard anyone can build on

How MCP Works Under the Hood

MCP is based on a simple client-server architecture:

MCP Client - Your agent (Claude Code, Cursor, Windsurf, Antigravity). The client sends requests to the server.
MCP Server - Software that exposes tools, resources, and prompts. The server connects to the data source (API, database, files).
Communication - Messages are exchanged over JSON-RPC 2.0, similar to the Language Server Protocol (LSP) familiar from the IDE world.

What an MCP Server Can Expose

Component	Description	Example
Tools	Functions the agent can invoke	"Get current USD exchange rate"
Resources	Data the agent can read	List of train stations
Prompts	Ready-made templates	"Analyze today's trading data"

Which Agents Support MCP

As of April 2026, MCP is supported by most leading coding agents:

Agent	MCP Support	Notes
Claude Code	Full	Creator of the protocol, full support from day one
Cursor	Full	Built-in MCP configuration support
Windsurf	Full	Support via config file
OpenAI (Codex, Agents SDK)	Full	Adopted in 2025
Google (Gemini CLI)	Full	Full support via Gemini CLI
GitHub Copilot	Full	Built-in support
Antigravity	Full	Support via config file

MCP Frequently Asked Questions

Is MCP free? Yes. MCP is an open standard and its development SDKs are open source. There is no cost to use the protocol itself. Costs may only come from external APIs that the server connects to.

Is MCP secure? MCP itself is a communication protocol. Security depends on the specific server. At Skills IL, every MCP server undergoes a security review before it is published in the directory.

What is the difference between MCP and a regular API? A regular API requires you to write code that connects to it. MCP lets the AI agent connect to the server directly, without you writing a single line of code. The agent discovers available tools and uses them as needed.

Do I need to know how to code to use MCP? No. Connecting an MCP server requires only adding a few lines of JSON to a config file. If you can copy and paste, you can use MCP.

The Skills IL MCP Directory

Our MCP Server Directory is a curated collection of open-source MCP servers that connect AI agents to Israeli data. Servers are organized by category:

Category	Examples
Government & Public Data	Knesset, Tax Authority, data.gov.il
Finance & Banking	Bank of Israel, Stock Exchange, exchange rates
Statistics & Economics	CBS (Central Bureau of Statistics), macro data
Healthcare & Medical	Ministry of Health, drugs database, nutrition
Real Estate & Land	Tabu (Land Registry), Israel Land Authority
Transportation	Israel Railways, Ben Gurion flights, public transit
Weather & Environment	IMS, air quality
Library & Archives	National Library, Sefaria
Shopping & Groceries	Shufersal, Rami Levy, price comparison
Security & Emergency	Home Front Command, shelters, Red Alert
Law & Legislation	Israeli state laws
Calendar	Hebrew calendar, holidays, Shabbat times
Tourism	Hiking trails in Israel

Each server is marked by status: Available (working and tested) or Community (built by the community).

Installation: Step by Step

Step 1: Choose a Server

Browse the MCP Server Directory and find a server that fits your needs. Click on a server card to see full details.

Step 2: Configure Your Agent

Each MCP server requires a configuration entry in your agent's settings file. The server page shows the exact configuration for each supported agent.

Claude Code (.mcp.json in your project folder):

{
  "mcpServers": {
    "boi-exchange": {
      "command": "npx",
      "args": ["-y", "@skills-il/boi-exchange-mcp"]
    }
  }
}

Cursor (.cursor/mcp.json):

{
  "mcpServers": {
    "boi-exchange": {
      "command": "npx",
      "args": ["-y", "@skills-il/boi-exchange-mcp"]
    }
  }
}

Windsurf (~/.codeium/windsurf/mcp_config.json):

{
  "mcpServers": {
    "boi-exchange": {
      "command": "npx",
      "args": ["-y", "@skills-il/boi-exchange-mcp"]
    }
  }
}

Step 3: Environment Variables

Some servers require API keys or environment variables. This information appears on the server page and in its GitHub documentation. Example:

{
  "mcpServers": {
    "my-server": {
      "command": "npx",
      "args": ["my-mcp-server"],
      "env": {
        "API_KEY": "your-api-key-here"
      }
    }
  }
}

Step 4: Verify

After adding the configuration and any required environment variables, restart your agent. You can verify the server is connected by asking your agent:

"What MCP tools are available to you?"

The agent should list the tools the server exposes.

Using Multiple Servers Together

MCP is designed to be composable. You can configure multiple servers together, and the agent gets access to all their tools:

{
  "mcpServers": {
    "boi-exchange": {
      "command": "npx",
      "args": ["-y", "@skills-il/boi-exchange-mcp"]
    },
    "ben-gurion-flights": {
      "command": "npx",
      "args": ["-y", "@skills-il/ben-gurion-flights-mcp"]
    },
    "israel-railways": {
      "command": "npx",
      "args": ["-y", "@skills-il/israel-railways-mcp"]
    }
  }
}

This way the agent can, for example, check Bank of Israel exchange rates, look up flights from Ben Gurion airport, and check Israel Railways schedules, all in a single conversation.

Debugging with MCP Inspector

MCP Inspector is a visual tool for testing and debugging MCP servers. Use it when something is not working as expected.

Installation and Usage

npx @modelcontextprotocol/inspector

This opens a browser interface that lets you:

Connect to a server - enter the server's start command and see if it starts successfully
View tools - list all tools the server exposes, including their parameters
Run tools - manually call tools with parameters you choose and see the result
Inspect resources - view resources the server provides
Monitor messages - watch the client-server communication in real time

Common Scenarios

Server does not connect:

Run the Inspector with the same command from your JSON config
Check that all environment variables are set
Look for error messages in the Inspector log

Tool returns an error:

Open the Inspector and call the tool directly
Check the parameters you are sending
Compare the result with the tool's documentation

Agent does not see the tools:

Make sure the config file is in the correct path
Restart the agent after updating the config
Check for JSON syntax errors in the config file

Tips for Effective Use

Start with one server - don't configure all servers at once. Start with one, make sure it works, then add more.
Read the documentation - each server offers different tools. Understanding the server's capabilities enables more precise usage.
Use clear names - when configuring multiple servers, choose clear key names (boi-exchange, israel-railways, ben-gurion-flights) so they are easy to identify.
Update regularly - MCP servers receive updates. Check the package changelog on npm or GitHub periodically, and clear your npx cache if you want to force the latest version.
Test with Inspector - before reporting a bug, check with MCP Inspector whether the issue is in the server or in your configuration.

Building Your Own MCP Server

You can build an MCP server using the official SDK:

TypeScript: @modelcontextprotocol/sdk package
Python: mcp package

For guides and examples, see the official MCP documentation.

If you built an MCP server for Israeli data and want to add it to our directory, reach out to us and we will be happy to include it.