garmin-mcp-server

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get_weight

Fetch weight measurements, BMI, and body fat percentage for a specified date range from Garmin Connect.

Instructions

Get weight/weigh-in data for a date range (YYYY-MM-DD). Returns weight measurements, BMI, body fat percentage if available.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "start_date": "<start_date>"
    },
    "name": "get_weight"
  }
}

Input Schema

Name	Required	Description	Default
`end_date`	No
`start_date`	Yes

Output Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Aug 30, 2026

TDQS

A3.5/5.0

Behavior3/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are present, so the description must convey behavioral expectations on its own. It discloses that BMI and body fat percentage are returned only 'if available,' which is a useful edge-case signal. However, it does not explain what happens when end_date is omitted, how inclusive the range is, units, timezone, or empty-result behavior.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is two short sentences with no superfluous content. The main scope ('weight/weigh-in data for a date range') is front-loaded, and the return highlights are placed second.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness3/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple two-parameter read tool with an output schema, the description is reasonably complete. It still leaves ambiguity around optional end_date semantics and sibling differentiation, so it is adequate but not thorough.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema has no property descriptions, so the description carries the burden of explaining the parameters. It specifies the YYYY-MM-DD format and that the request is date-bounded, which helps for start_date and end_date. It does not explain end_date's optional/default behavior or whether the range is inclusive.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly identifies the operation (get), the resource (weight/weigh-in data), and the scope (date range with YYYY-MM-DD format). It also names the returned metrics, making the tool's purpose unambiguous. It does not explicitly distinguish itself from get_body_composition, but the weight focus is distinct enough.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies this tool is for retrieving weight data over a date range, but it gives no explicit when-to-use/when-not-to-use guidance or references to alternatives. Given the large sibling list, an agent has to infer this is the right tool for weight queries and not for body composition or daily summary.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.