log_body_fat · Fitbit Googlehealth MCP: Risk & Policy

WHAT IT DOES

What log_body_fat does on Fitbit Googlehealth

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

WHY IT NEEDS A POLICY

Why log_body_fat needs a policy

This tool writes a new body fat measurement to the user's Fitbit health record. It is a reversible write operation (a sibling tool 'delete_body_fat_log' exists to undo it). No code execution, financial transaction, or irreversible destruction is involved. Severity is low as misuse only affects personal health tracking data.

From the tool's definition 'Record a body-fat percentage reading' — creates a new body fat log entry

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

log_body_fat Rate-limited

log_body_fat 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": {
    "log_body_fat": {
      "limits": [
        {
          "counter": "log_body_fat_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 Fitbit Googlehealth, so you can run agents against it safely.

FAQ

Questions about log_body_fat

What does the log_body_fat tool do? +

Record a body-fat percentage reading (e.g. from a smart scale). It is categorised as a Write tool in the Fitbit Googlehealth MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on log_body_fat? +

Register the Fitbit Googlehealth MCP server in PolicyLayer and add a rule for log_body_fat: 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 Fitbit Googlehealth. Nothing to install.

What risk level is log_body_fat? +

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

Can I rate-limit log_body_fat? +

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

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

log_body_fat is provided by the Fitbit Googlehealth MCP server (tachibanayu24/fitbit-googlehealth-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.