switch_session · FOL Prover MCP Server MCP: Risk & Policy

WHAT IT DOES

What switch_session does on FOL Prover MCP Server

AI agents use switch_session to create or update resources in FOL Prover MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your FOL Prover MCP Server environment.

WHY IT NEEDS A POLICY

Why switch_session needs a policy

Switching sessions changes the active session in the MCP server's session management system, which is a state modification. This is not destructive (the session still exists), not financial, and not Execute in the sense of running external code—it's a management operation that modifies application state. It aligns with Write category as a reversible state-changing action.

From the tool's definition The tool description states it 'switch[es] to a different session', which modifies the current state of the prover session context. This is a reversible state change operation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

switch_session Rate-limited

switch_session 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_session": {
      "limits": [
        {
          "counter": "switch_session_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 FOL Prover MCP Server, so you can run agents against it safely.

FAQ

Questions about switch_session

What does the switch_session tool do? +

Switch to a different session. It is categorised as a Write tool in the FOL Prover MCP Server 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_session? +

Register the FOL Prover MCP Server MCP server in PolicyLayer and add a rule for switch_session: 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 FOL Prover MCP Server. Nothing to install.

What risk level is switch_session? +

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

Can I rate-limit switch_session? +

Yes. Add a rate_limit block to the switch_session 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_session completely? +

Set action: deny in the PolicyLayer policy for switch_session. 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_session? +

switch_session is provided by the FOL Prover MCP Server MCP server (newjerseystyle/folprover-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.