switch_server · FHIR Careplan MCP: Risk & Policy

WHAT IT DOES

What switch_server does on FHIR Careplan

AI agents use switch_server to create or update resources in FHIR Careplan — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your FHIR Careplan environment.

WHY IT NEEDS A POLICY

Why switch_server needs a policy

Switching the active FHIR server changes the configuration/state of the MCP server, directing all subsequent queries and operations to a different backend. This is a reversible state change (you can switch back), making it a Write/configuration-change action.

From the tool's definition Switch to a different FHIR server

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

switch_server Rate-limited

switch_server stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "switch_server": {
      "limits": [
        {
          "counter": "switch_server_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches FHIR Careplan, so you can run agents against it safely.

FAQ

Questions about switch_server

What does the switch_server tool do? +

Switch to a different FHIR server. It is categorised as a Write tool in the FHIR Careplan MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on switch_server? +

Register the FHIR Careplan MCP server in PolicyLayer and add a rule for switch_server: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches FHIR Careplan. Nothing to install.

What risk level is switch_server? +

switch_server is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit switch_server? +

Yes. Add a rate_limit block to the switch_server rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block switch_server completely? +

Set action: deny in the PolicyLayer policy for switch_server. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides switch_server? +

switch_server is provided by the FHIR Careplan MCP server (kushagra-dutta/fhir-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.