log_activity · Fitbit Googlehealth MCP: Risk & Policy

WHAT IT DOES

What log_activity does on Fitbit Googlehealth

AI agents use log_activity 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_activity needs a policy

This tool writes new activity/workout data to the user's Fitbit account. It is reversible (a sibling tool 'delete_activity_log' exists), so it falls under Write rather than Destructive. Misuse could result in inaccurate health records, but the blast radius is limited to personal health data.

From the tool's definition 'Record a workout that Fitbit did not auto-detect' — creates a new activity log entry

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

log_activity Rate-limited

log_activity 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_activity": {
      "limits": [
        {
          "counter": "log_activity_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_activity

What does the log_activity tool do? +

Record a workout that Fitbit did not auto-detect. Provide either. 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_activity? +

Register the Fitbit Googlehealth MCP server in PolicyLayer and add a rule for log_activity: 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_activity? +

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

Can I rate-limit log_activity? +

Yes. Add a rate_limit block to the log_activity 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_activity completely? +

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

log_activity 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.