start_session · TDD- MCP: Risk & Policy

WHAT IT DOES

What start_session does on TDD-MCP

AI agents use start_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 start_session needs a policy

Based on the tool name and server context, 'start_session' likely creates a new TDD session with associated state, which is a reversible Write operation. The empty description lowers confidence. Sibling tools like 'end_session', 'pause_session', 'resume_session' confirm this is session lifecycle management. Severity is low as misuse only affects development workflow state.

From the tool's definition Tool name 'start_session' on a TDD session management server; description is empty.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

start_session Rate-limited

start_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": {
    "start_session": {
      "limits": [
        {
          "counter": "start_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 start_session

What does the start_session tool do? +

start_session. 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 start_session? +

Register the TDD- MCP server in PolicyLayer and add a rule for start_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 start_session? +

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

Can I rate-limit start_session? +

Yes. Add a rate_limit block to the start_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 start_session completely? +

Set action: deny in the PolicyLayer policy for start_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 start_session? +

start_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.