update_body_measurement · Hevy MCP: Risk & Policy

WHAT IT DOES

What update_body_measurement does on Hevy

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

WHY IT NEEDS A POLICY

Why update_body_measurement needs a policy

This tool modifies user fitness tracking data (body measurements) but does not delete or irreversibly destroy information. The change can be undone by updating again to a previous value, making it Write rather than Destructive. Severity is medium because misuse could corrupt personal health metrics, but the data remains recoverable and there is no financial or system-level impact.

From the tool's definition Tool name 'update_body_measurement' and description 'Update body measurement entry for a date' explicitly indicate modification of existing data. The action is reversible (prior measurements can be corrected or overwritten with new values).

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

update_body_measurement Rate-limited

update_body_measurement 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": {
    "update_body_measurement": {
      "limits": [
        {
          "counter": "update_body_measurement_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 Hevy, so you can run agents against it safely.

FAQ

Questions about update_body_measurement

What does the update_body_measurement tool do? +

Update body measurement entry for a date (YYYY-MM-DD). It is categorised as a Write tool in the Hevy MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on update_body_measurement? +

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

What risk level is update_body_measurement? +

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

Can I rate-limit update_body_measurement? +

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

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

update_body_measurement is provided by the Hevy MCP server (srdjancodes/hevy-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.