upsert_meal · MCP Logger MCP: Risk & Policy

WHAT IT DOES

What upsert_meal does on MCP Logger

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

WHY IT NEEDS A POLICY

Why upsert_meal needs a policy

This tool creates new meal records or modifies existing ones in the fitness tracking database, which are standard Write operations. The changes are reversible (meals can be deleted or updated again), and the blast radius is moderate—an AI agent could log incorrect meals or nutritional data, affecting user health tracking accuracy, but cannot permanently destroy data or trigger financial transactions.

From the tool's definition Tool name 'upsert_meal' and description 'Create or update a meal within a nutrition day' explicitly indicate reversible creation or modification of data.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

upsert_meal Rate-limited

upsert_meal 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": {
    "upsert_meal": {
      "limits": [
        {
          "counter": "upsert_meal_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 Logger, so you can run agents against it safely.

FAQ

Questions about upsert_meal

What does the upsert_meal tool do? +

Create or update a meal within a nutrition day. It is categorised as a Write tool in the MCP Logger MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on upsert_meal? +

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

What risk level is upsert_meal? +

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

Can I rate-limit upsert_meal? +

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

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

upsert_meal is provided by the MCP Logger MCP server (johnzolton/mcp-logger). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.