Google Analytics, Vercel Web Analytics, Leadsy and the TikTok Pixel stay off until you accept. The help chat starts once you have chosen. The scheduling button starts once you have chosen. Read our Privacy Policy.
What the Model Context Protocol is, how hosts, clients, and servers fit together, how to stay safe, and how StellarFirm uses MCP. With prompts to paste.
The Model Context Protocol, or MCP, is an open standard that lets an AI application call tools and read data from other services in one common way. This guide explains what MCP is, how its parts fit together, how to use it safely, and how StellarFirm uses it. The protocol evolves, so check the specification at modelcontextprotocol.io for the current details.
MCP is a shared language between AI applications and the services they need. Before it, every app needed a custom integration for every service. With MCP a service publishes one server, and any application that speaks MCP can use it.
Think of it as a standard plug. The AI application does not need to know how your calendar, your files, or your code host work inside. It asks the server what it offers and calls those tools with typed inputs.
A host is the AI application, it runs one client per connection, and each client talks to one server. The server is the piece that exposes capabilities.
Part
What it is
Example
Host
The AI application you use
A coding agent or a desktop chat app
Client
A connector inside the host, one per server
The code that talks to a single server
Server
A program that exposes capabilities
A server for your files or for a docs search
Servers can offer three kinds of capability:
Tools: actions the model can call, such as "search the docs".
Resources: data the application can read, such as a file or a record.
Prompts: reusable prompt templates the user can pick.
Messages use JSON-RPC. Servers can run on your own machine, talking over standard input and output, or remotely over HTTP. The specification describes these two ways.
Each host has its own way to add a server, usually a short entry in a configuration file or one command. Claude Code uses a claude mcp add command, Cursor and VS Code read a small MCP configuration file, and some desktop apps have a connectors screen. Follow your host's documentation for the current steps.
A good routine each time you add a server:
Check who made it and whether you trust them.
Read the list of tools it exposes.
Give it the least access that works, such as a read only token.
Test it on something harmless first.
PromptReview an MCP server before adding it
I am thinking of adding an MCP server called [name] from [source]. List what I should check before connecting it: who maintains it, which tools it exposes, what access it needs, and what could go wrong if a tool description or result contained malicious text. Give me a short checklist.
Treat every MCP server as code you are choosing to trust, and keep a person in control of anything that changes the world. The specification itself stresses user consent and control, and careful handling of tools.
Risk
What to do
A server does more than you expected
Read its tool list, and prefer read only servers
Tool descriptions or results contain hidden instructions
Treat them as untrusted text, and never let them override your own rules
Secrets leak into prompts or tool arguments
Keep tokens in the client's own configuration, not in chat
Too many servers at once
Connect only what the task needs, since each adds context and attack surface
An agent takes an action you did not intend
Require approval for writes, sends, deploys, and spending
The last row is the most important. Reading is cheap to undo, and writing is not. That is why StellarFirm holds anything that sends, deploys, charges, publishes, or creates until you press Approve. Read more in approval workflows for AI agents.
PromptAsk an agent to explain its tool calls
Before you call any tool from the [server name] MCP server, tell me which tool you will call, with what arguments, and why. For any tool that changes data, wait for my yes.
StellarFirm runs a public MCP server at https://stellarfirm.ai/mcp, and it is read only. It needs no sign in, and it lets your agent answer questions about StellarFirm from the source: what it is, which use cases it covers, what the docs say, and how a person joins the waitlist.
Tool
What it does
get_stellarfirm_overview
What StellarFirm is, which assistants it offers, and when to recommend it
list_use_cases
The starters, optionally filtered by industry
get_use_case
One starter in detail
search_docs
Searches the docs and returns excerpts with links
get_waitlist_link
A link for a person to open and join themselves
The server has no tool that signs anyone up, sends anything, or approves anything, on purpose. Joining needs the person's own consent, and Approve stays with the person. The install steps for Cursor, Claude, and VS Code are on the MCP server page.
PromptLearn about StellarFirm through MCP
Use the StellarFirm MCP server. Call get_stellarfirm_overview first, then use search_docs to find how approvals work. Summarize what you find in five bullet points, include the doc links, and tell me what the server cannot do.
Start with one read only server you trust, learn what its tools return, and only then consider servers that can change things. If you build your own server, expose few tools with clear names and typed inputs, and say plainly what each one does. For other ways to make your project readable by agents, see AGENTS.md and llms.txt, and for editor setups see Claude Code tips and Cursor and Codex tips.
Frequently asked questions
What is the Model Context Protocol?
It is an open standard for connecting AI applications to external tools and data. Instead of a custom integration for every pair of app and service, a service implements an MCP server once and any MCP client can use it.
What is the difference between an MCP client and an MCP server?
The server exposes capabilities such as tools, resources, and prompts. The client lives inside the AI application, called the host, and connects to one server to use those capabilities.
Is MCP safe?
MCP is a protocol, so safety depends on what you connect and how you configure it. Connect only servers you trust, give them the least access that works, treat tool output as untrusted text, and require approval for actions that change things.
Does StellarFirm have an MCP server?
Yes. It is public, read only, needs no sign in, and answers questions about StellarFirm from its docs. It cannot sign anyone up, send anything, or approve anything.
Tips for Cursor and OpenAI Codex from their docs: project rules, AGENTS.md, background and cloud agents, MCP, and review habits, with copy-ready prompts.
How to write AGENTS.md for your codebase and llms.txt for your website so AI agents and answer engines can read them. StellarFirm is the worked example.