simulate_agent_replay · Todos MCP: Risk & Policy

WHAT IT DOES

What simulate_agent_replay does on Todos

AI agents invoke simulate_agent_replay to trigger actions in Todos. 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 simulate_agent_replay needs a policy

This tool executes recorded agent contexts and run fixtures (simulating agent behavior and code execution), making it an Execute category tool. While the dry-run nature and lack of database mutations reduce severity below a typical Execute operation, replay of arbitrary recorded contexts could still pose risks if the recorded operations include harmful commands or side effects to external systems.

From the tool's definition Tool description states it performs a 'replay' of a 'recorded local agent context pack or run fixture', which involves executing/simulating recorded operations.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

simulate_agent_replay Rate-limited

simulate_agent_replay 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": {
    "simulate_agent_replay": {
      "limits": [
        {
          "counter": "simulate_agent_replay_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 Todos, so you can run agents against it safely.

FAQ

Questions about simulate_agent_replay

What does the simulate_agent_replay tool do? +

Dry-run replay a recorded local agent context pack or run fixture without mutating the task database. It is categorised as a Execute tool in the Todos MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on simulate_agent_replay? +

Register the Todos MCP server in PolicyLayer and add a rule for simulate_agent_replay: 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 Todos. Nothing to install.

What risk level is simulate_agent_replay? +

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

Can I rate-limit simulate_agent_replay? +

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

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

simulate_agent_replay is provided by the Todos MCP server (@hasna/todos). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.