mcp-client-integration

Consume an MCP Server

Far more people install servers than write them, and installing one is the part with the risk. An MCP server is code that runs on your machine, holds your credentials, and is invoked by a model that can be persuaded. A friendly description is not a safety property.

Evaluate Before Installing

Five questions, cheapest disqualifier first.

1. Who publishes it? A vendor publishing a server for their own API has a reputation at stake. An unaffiliated wrapper of that same API does not. Check whether the vendor ships one before reaching for a third-party copy.

2. What does it execute? Read the install command. npx some-server fetches and runs code at every launch, resolving to whatever the registry serves that day. A pinned version or a vendored build is a different risk profile entirely.

3. What credentials does it want? A server asking for a token scoped wider than its tools need is either careless or worse. A read-only integration should not require write scope.

4. What tools does it expose? Install it, list the tools, and read them before wiring it into anything that matters. Look for destructive operations that are not annotated — that combination means the author did not think about the host's ability to gate them.

5. Is it maintained? Last commit, open issues, whether it tracks SDK releases. An unmaintained server pinned to an old SDK is a dependency that will break on a protocol change nobody is watching for.

Register It

For a Copilot plugin, declare it in plugin.json:

{
  "mcpServers": {
    "their-server": {
      "type": "stdio",
      "command": "node",
      "args": ["node_modules/their-server/dist/index.js"],
      "env": { "THEIR_API_TOKEN": "${env:THEIR_API_TOKEN}" }
    }
  }
}

${env:VAR} reads from the environment at launch, so the token stays out of the committed file. Restart the host after changing this block — hosts read it at startup.

Prefer a concrete path over a package runner. node node_modules/.../index.js runs what you installed and reviewed; npx their-server runs what the registry serves at that moment.