track_identifier · MCP Pyrefly MCP: Risk & Policy

WHAT IT DOES

What track_identifier does on MCP Pyrefly

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

WHY IT NEEDS A POLICY

Why track_identifier needs a policy

The tool writes/modifies state by registering an identifier into a tracking system for consistency checks. This is a reversible state change (adding tracking metadata), not a destructive or executable action. Severity is low as it only manages internal tracking state with minimal blast radius.

From the tool's definition Explicitly track an identifier for consistency checking

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

track_identifier Rate-limited

track_identifier 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": {
    "track_identifier": {
      "limits": [
        {
          "counter": "track_identifier_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 MCP Pyrefly, so you can run agents against it safely.

FAQ

Questions about track_identifier

What does the track_identifier tool do? +

Explicitly track an identifier for consistency checking. It is categorised as a Write tool in the MCP Pyrefly MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on track_identifier? +

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

What risk level is track_identifier? +

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

Can I rate-limit track_identifier? +

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

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

track_identifier is provided by the MCP Pyrefly MCP server (kimasplund/mcp-pyrefly). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.