add_hydration_data · Garmin MCP Server MCP: Risk & Policy

WHAT IT DOES

What add_hydration_data does on Garmin MCP Server

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

WHY IT NEEDS A POLICY

Why add_hydration_data needs a policy

This tool creates or modifies hydration records reversibly within Garmin Connect. It is a Write operation because the user can later delete, update, or override the hydration entry. Severity is low because hydration data is non-financial, non-destructive, and a misuse (adding false hydration records) has minimal blast radius compared to financial or data-deletion risks.

From the tool's definition Tool name 'add_hydration_data' and description 'Add hydration data' indicate creation/modification of user health data in Garmin Connect. Consistent with sibling tools like 'add_body_composition' and 'add_weigh_in' which are Write operations.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

add_hydration_data Rate-limited

add_hydration_data 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_hydration_data": {
      "limits": [
        {
          "counter": "add_hydration_data_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 Garmin MCP Server, so you can run agents against it safely.

FAQ

Questions about add_hydration_data

What does the add_hydration_data tool do? +

Add hydration data. It is categorised as a Write tool in the Garmin MCP Server 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_hydration_data? +

Register the Garmin MCP Server MCP server in PolicyLayer and add a rule for add_hydration_data: 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 Garmin MCP Server. Nothing to install.

What risk level is add_hydration_data? +

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

Can I rate-limit add_hydration_data? +

Yes. Add a rate_limit block to the add_hydration_data 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_hydration_data completely? +

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

add_hydration_data is provided by the Garmin MCP Server MCP server (jbaker48/garmin-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.