What is MCP? A Beginner’s Guide to the Model Context Protocol

June 12, 2025

Large language models (LLMs) like GPT-4 and Claude are astonishingly capable — they can write code, summarize documents, and answer complex questions. But they’re missing something big: structured access to your real-world tools and data.

You might have files in Google Drive, notes in Notion, or metrics in a SQL database. But connecting an AI model to those services in a secure, scalable way? That’s still frustratingly bespoke. Developers end up building custom integrations from scratch, repeating the same work across different apps and AI platforms. It’s inefficient, brittle, and hard to maintain.

This is the challenge the Model Context Protocol (MCP) was built to solve.

MCP stands for Model Context Protocol — an open standard that allows AI models (or agents) to securely interact with tools and data through a shared, structured interface.

Think of it as a USB-C for AI tooling: one universal protocol that lets any compliant AI system connect to any compatible server, tool, or data source.

Instead of building custom APIs or plugins for every integration, developers can wrap a tool in an MCP server — a lightweight service that exposes capabilities in a format LLMs understand. The AI client (like Claude, or a local orchestrator) then speaks to that server using a standardized message format (JSON-RPC), allowing dynamic interaction.

Without MCP, AI integrations tend to fall into a few frustrating categories:

  • Bespoke API wrappers: You write custom code to connect a model to each system.

  • LLM-specific plugins: You use proprietary plugin systems (e.g. ChatGPT plugins), but they only work on one platform.

  • Context hacking: You stuff relevant info into the prompt (via Retrieval-Augmented Generation), but the model can’t take action.

These solutions are useful, but siloed. Each tool requires custom work. You can’t swap models easily. And the AI is either passive (just reading) or awkwardly triggering scripts with brittle prompt-engineered calls.

MCP standardizes everything.

With it:

  • A model can dynamically call a tool, fetch a resource, or apply a reusable prompt template.

  • Tools and models can be developed independently — and still work together.

  • Developers don’t have to rebuild integrations when they change AI models or platforms.

The result? Faster development, greater interoperability, and a much smoother path to AI agents that actually do things.

MCP defines a simple client–server architecture:

  • The MCP client is embedded in the AI agent, orchestrator, or application.

  • The MCP server wraps a specific capability (like file access, Slack messaging, or database queries).

Each MCP server exposes one or more of the following:

  1. Tools — Actions the model can invoke, like searchMessages() or runQuery().

  2. Resources — Structured data the model can read, like a markdown document or spreadsheet.

  3. Prompts — Reusable prompt snippets or task templates, like “summarize meeting notes”.

Everything is communicated in structured JSON, and each interaction is tagged by control type (model-controlled, user-controlled, application-controlled) to ensure safe, auditable behavior.

This structure is what makes MCP integrations dynamic, flexible, and reusable — with far less glue code.

MCP was introduced by Anthropic in late 2024 and has already seen strong uptake:

  • Anthropic’s Claude Desktop app ships with built-in MCP support.

  • Replit, Notion, and Sourcegraph have open-sourced their own MCP servers.

  • Developers have built hundreds of servers for tools like Google Drive, GitHub, Slack, Docker, Postgres, and more.

  • OpenAI has committed to supporting MCP in its Agent SDK and ChatGPT desktop app.

This isn’t just a theoretical spec- it’s rapidly becoming the way to connect AI to external tools and workflows.

Let’s say your AI assistant is helping manage a project. It needs to:

  • Check an open GitHub issue

  • Update a Notion task list

  • Summarize a recent customer support ticket

With MCP:

  • It connects to an MCP GitHub server and calls a getIssue() tool.

  • It reads a resource from a Notion MCP server.

  • It uses a summarize() prompt template from a support ticket server.

All of this happens through one unified protocol, with tools and resources discovered at runtime — no hardcoded integrations or manual prompt engineering needed.

As elegant as MCP is, there’s a practical hurdle: running and managing MCP servers.

Each tool you want to connect to needs its own server process. Setting those up — managing ports, installing dependencies, handling environment variables — can be a pain, especially for newcomers.

That’s where MCP Now comes in.

MCP Now is a desktop app, a control panel for the MCP ecosystem. It helps you:

  • Discover existing servers (via categories, rankings, search)

  • Install them with one click (no terminal commands needed)

  • Manage your server profiles and hosts from a single dashboard

  • Monitor and debug tool interactions in real-time

  • Hot-swap servers without restarting your AI workflows

  • Share your setups with friends

In short, MCP Now removes the operational friction — so you can spend less time fiddling with servers and more time building cool AI stuff.

Let’s recap what MCP offers:

  • Standardization: One format to rule them all.

  • Interoperability: Any compliant model can use any compliant tool.

  • Speed: Build AI-powered apps faster by reusing prebuilt servers.

  • Scalability: New tools can be added without retraining or redeploying.

  • Security: Fine-grained control over what data is accessed and how.

And when paired with MCP Now, you get:

  • Rapid onboarding

  • Easy server discovery

  • Debugging and visibility

  • Team sharing and collaboration

This isn’t just a better way to integrate AI — it’s a better foundation for building the next generation of AI-first applications.

In this guide, we covered:

  • What MCP is and the problem it solves

  • How it works at a high level

  • Why it’s gaining momentum

  • How MCP Now makes it accessible to developers

But there’s more to explore.

In Part 2: Why MCP Beats Traditional Integrations, we’ll dive deeper into how MCP compares to other approaches like RAG, plugins, and custom APIs — and when you should use each.

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