add_user_topic · Metis Public Health MCP: Risk & Policy

WHAT IT DOES

What add_user_topic does on Metis Public Health

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

WHY IT NEEDS A POLICY

Why add_user_topic needs a policy

This tool creates or registers a new topic entry in the user's tracking system for monitoring publications. It modifies the user's stored preferences/topics reversibly—users can remove or change tracked topics. It has no destructive, financial, or execute characteristics. The blast radius is minimal: worst case, irrelevant publication alerts are generated.

From the tool's definition Tool name 'add_user_topic' and description 'Add a topic to track for new publications' indicate creation of new tracking data. The verb 'Add' and the action of creating a topic entry are characteristic of Write operations.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

add_user_topic Rate-limited

add_user_topic 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": {
    "add_user_topic": {
      "limits": [
        {
          "counter": "add_user_topic_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 Metis Public Health, so you can run agents against it safely.

FAQ

Questions about add_user_topic

What does the add_user_topic tool do? +

Add a topic to track for new publications. It is categorised as a Write tool in the Metis Public Health MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on add_user_topic? +

Register the Metis Public Health MCP server in PolicyLayer and add a rule for add_user_topic: 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 Metis Public Health. Nothing to install.

What risk level is add_user_topic? +

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

Can I rate-limit add_user_topic? +

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

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

add_user_topic is provided by the Metis Public Health MCP server (sveritg/metis_ph). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.