MCP in practice: what it really changes for your agents

MCP (Model Context Protocol) has become a de facto standard for connecting LLMs to external tools. Here’s what it concretely changes in how you build agents.

The problem MCP solves

Before MCP, connecting an LLM to your ticketing system meant rewriting the same plumbing code for every project. Non-reusable, non-standardized.

MCP creates a common interface: an MCP server exposes tools, and any compatible client can use them without rewriting the integration layer.

How it works in practice

An MCP server is a process that exposes tools via a standardized protocol. Claude (or any MCP client) can discover these tools and call them.

Concrete example: you have an internal project management system. You create an MCP server that exposes:

list_projects()     → active projects list
get_project(id)     → project details
create_task(...)    → create a task
update_status(...)  → update a status

Once this server is deployed, Claude can call these tools natively in any conversation or agent.

The open source ecosystem

The good news: you probably don’t need to create your own MCP server for most common tools. The community has already done the work:

• GitHub, Notion, Google Drive, Slack: official servers available
• SQL databases, file systems, REST APIs: generic servers
• Monitoring tools, ticketing systems: community contributors

What this changes in architecture

Without MCP, every agent you build reinvents its own integration layer. With MCP, you cleanly separate:

• Agents: logic, prompts, orchestration
• MCP servers: connections to external systems

Limits to know

Latency adds up. Each MCP call is a network round trip. On an agent making 5 sequential tool calls, this can become significant.

Errors must be well handled. Define explicit fallback behaviors.

Context has a size limit. Tool results are injected into context. On large returns, you can saturate the context window quickly. Paginate and filter on the MCP server side.

Where to start

1. Claude Desktop supports MCP natively — simplest way to experiment
2. Install an existing MCP server (filesystem or GitHub to start)
3. Observe how Claude uses it
4. Then consider writing your own server