close_child_session · MCP Gateway (Parent MCP Server) MCP

WHAT IT DOES

What close_child_session does on MCP Gateway (Parent MCP Server)

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

WHY IT NEEDS A POLICY

Why close_child_session needs a policy

An AI agent can call close_child_session faster than any human can review — one bad instruction and it creates or modifies resources in MCP Gateway (Parent MCP Server) by the hundred, each call as confident as the last.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

close_child_session Rate-limited

close_child_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": {
    "close_child_session": {
      "limits": [
        {
          "counter": "close_child_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 MCP Gateway (Parent MCP Server), so you can run agents against it safely.

FAQ

Questions about close_child_session

What does the close_child_session tool do? +

指定した子サーバーのセッションをクローズする。. It is categorised as a Write tool in the MCP Gateway (Parent 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 close_child_session? +

Register the MCP Gateway (Parent MCP Server) MCP server in PolicyLayer and add a rule for close_child_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 MCP Gateway (Parent MCP Server). Nothing to install.

What risk level is close_child_session? +

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

Can I rate-limit close_child_session? +

Yes. Add a rate_limit block to the close_child_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 close_child_session completely? +

Set action: deny in the PolicyLayer policy for close_child_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 close_child_session? +

close_child_session is provided by the MCP Gateway (Parent MCP Server) MCP server (tomcat2357/mcpgateway). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.