update_watch_rule · Todos MCP: Risk & Policy

WHAT IT DOES

What update_watch_rule does on Todos

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

WHY IT NEEDS A POLICY

Why update_watch_rule needs a policy

This tool modifies existing watch rules (a reversible write operation) rather than reading, executing arbitrary commands, or destructively deleting data. The impact is localized to terminal watch configuration.

From the tool's definition Tool name 'update_watch_rule' and description 'Update a local terminal watch rule' indicate modification of existing configuration/rules data.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_watch_rule Rate-limited

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

FAQ

Questions about update_watch_rule

What does the update_watch_rule tool do? +

Update a local terminal watch rule. It is categorised as a Write tool in the Todos MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on update_watch_rule? +

Register the Todos MCP server in PolicyLayer and add a rule for update_watch_rule: 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 update_watch_rule? +

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

Can I rate-limit update_watch_rule? +

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

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

update_watch_rule 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.