set_task_custom_field · Todos MCP: Risk & Policy

WHAT IT DOES

What set_task_custom_field does on Todos

AI agents use set_task_custom_field 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 set_task_custom_field needs a policy

This tool creates or modifies task data reversibly by updating a custom field value. It does not retrieve data (Read), execute external operations (Execute), irreversibly delete data (Destructive), or involve financial transactions (Financial).

From the tool's definition Tool name "set_task_custom_field" and description "Set a custom field value on a task" indicate modification of task metadata. The verb "set" combined with "value on a task" demonstrates data modification (Write category) rather than retrieval or deletion.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

set_task_custom_field Rate-limited

set_task_custom_field 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": {
    "set_task_custom_field": {
      "limits": [
        {
          "counter": "set_task_custom_field_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 set_task_custom_field

What does the set_task_custom_field tool do? +

Set a custom field value on a task. 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 set_task_custom_field? +

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

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

Can I rate-limit set_task_custom_field? +

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

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

set_task_custom_field 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.