end_session · TDD- MCP: Risk & Policy

WHAT IT DOES

What end_session does on TDD-MCP

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

WHY IT NEEDS A POLICY

Why end_session needs a policy

This tool performs a write operation by modifying session state (marking a session as ended/inactive). While it does not create new data or delete historical records, it irreversibly changes the status of the current session. It is not a Read operation because it has side effects beyond querying. It is not Destructive because the session data and history remain intact (the history tool is available as a sibling).

From the tool's definition The tool description states it will "End the current active session and return summary." Ending a session modifies the state of the session management system by terminating an active session, which is a state change operation.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

end_session Rate-limited

end_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": {
    "end_session": {
      "limits": [
        {
          "counter": "end_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 TDD-MCP, so you can run agents against it safely.

FAQ

Questions about end_session

What does the end_session tool do? +

End the current active session and return summary. It is categorised as a Write tool in the TDD-MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on end_session? +

Register the TDD- MCP server in PolicyLayer and add a rule for end_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 TDD-MCP. Nothing to install.

What risk level is end_session? +

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

Can I rate-limit end_session? +

Yes. Add a rate_limit block to the end_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 end_session completely? +

Set action: deny in the PolicyLayer policy for end_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 end_session? +

end_session is provided by the TDD- MCP server (tinmancoding/tdd-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.