create_milestone · Plane MCP: Risk & Policy

WHAT IT DOES

What create_milestone does on Plane

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

WHY IT NEEDS A POLICY

Why create_milestone needs a policy

The 'create_milestone' tool creates a new milestone object in Plane, which is a reversible write operation. It modifies project state by adding data but does not execute arbitrary code, delete data, or move money. The blast radius is medium because creating spurious milestones could clutter project timelines and confuse stakeholders, but the operation is easily undone.

From the tool's definition Tool name 'create_milestone' indicates creation of a milestone entity. Based on sibling tools on the Plane server (create_cycle, create_initiative, create_project, etc.), this is a data creation operation within a project management system.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_milestone Rate-limited

create_milestone 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": {
    "create_milestone": {
      "limits": [
        {
          "counter": "create_milestone_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 Plane, so you can run agents against it safely.

FAQ

Questions about create_milestone

What does the create_milestone tool do? +

create_milestone. It is categorised as a Write tool in the Plane MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on create_milestone? +

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

What risk level is create_milestone? +

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

Can I rate-limit create_milestone? +

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

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

create_milestone is provided by the Plane MCP server (@makeplane/plane-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.