create_session_tool · Open MCP: Risk & Policy

WHAT IT DOES

What create_session_tool does on Openmcp

AI agents invoke create_session_tool to trigger actions in Openmcp. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why create_session_tool needs a policy

Given the server context of web automation via MCP, a 'create_session_tool' likely initializes a browser or web session, which is an external operation with side effects (resource allocation, network activity). This falls under Execute. However, the empty description significantly lowers confidence — it could be a simple Write (creating a session record) or even Read.

From the tool's definition Tool name 'create_session_tool' on a server described as enabling web automation (browsing, clicking, typing, screenshots). Description is empty.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_session_tool Rate-limited

create_session_tool stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "create_session_tool": {
      "limits": [
        {
          "counter": "create_session_tool_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

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

FAQ

Questions about create_session_tool

What does the create_session_tool tool do? +

create_session_tool. It is categorised as a Execute tool in the Openmcp MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on create_session_tool? +

Register the Open MCP server in PolicyLayer and add a rule for create_session_tool: 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 Openmcp. Nothing to install.

What risk level is create_session_tool? +

create_session_tool is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit create_session_tool? +

Yes. Add a rate_limit block to the create_session_tool 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 create_session_tool completely? +

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

create_session_tool is provided by the Open MCP server (openmcp-pro/openmcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.