todo_update · Todo MCP: Risk & Policy

WHAT IT DOES

What todo_update does on Todo MCP

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

WHY IT NEEDS A POLICY

Why todo_update needs a policy

The tool creates or modifies data reversibly—it updates task metadata like completion status, priority, tags, or due dates. These changes can be undone by subsequent updates. It does not delete data (Destructive), execute code (Execute), or involve financial transactions (Financial). Severity is low because the blast radius of misuse is confined to task data that is easily correctable.

From the tool's definition Tool description states 'edit an existing todo', which is a modification operation. Sibling tools include 'todo_add' (Write), 'todo_delete' (Destructive), and 'todo_list' (Read), positioning 'todo_update' as a reversible data modification.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

todo_update Rate-limited

todo_update 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": {
    "todo_update": {
      "limits": [
        {
          "counter": "todo_update_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 Todo MCP, so you can run agents against it safely.

FAQ

Questions about todo_update

What does the todo_update tool do? +

Use this when the user wants to edit an existing todo. It is categorised as a Write tool in the Todo 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 todo_update? +

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

What risk level is todo_update? +

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

Can I rate-limit todo_update? +

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

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

todo_update is provided by the Todo MCP server (peterfabakker/todo-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.