derive_subgoal · Planning System MCP Server MCP

WHAT IT DOES

What derive_subgoal does on Planning System MCP Server

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

WHY IT NEEDS A POLICY

Why derive_subgoal needs a policy

An AI agent can call derive_subgoal faster than any human can review — one bad instruction and it creates or modifies resources in Planning System MCP Server by the hundred, each call as confident as the last.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

derive_subgoal Rate-limited

derive_subgoal 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": {
    "derive_subgoal": {
      "limits": [
        {
          "counter": "derive_subgoal_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 Planning System MCP Server, so you can run agents against it safely.

FAQ

Questions about derive_subgoal

What does the derive_subgoal tool do? +

Create a sub-goal under an existing parent goal (parent_goal_id required). It is categorised as a Write tool in the Planning System MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on derive_subgoal? +

Register the Planning System MCP Server MCP server in PolicyLayer and add a rule for derive_subgoal: 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 Planning System MCP Server. Nothing to install.

What risk level is derive_subgoal? +

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

Can I rate-limit derive_subgoal? +

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

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

derive_subgoal is provided by the Planning System MCP Server MCP server (tagents/agent-planner-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.