Retrieve the account's primary training device to identify which Garmin device is used for training metrics and workouts.
The account's primary training device.
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered structurally. The description adds nothing behavioral beyond that — no indication of what is returned, whether a device must be configured, or what happens if no primary device exists.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
A single short sentence with no filler and the key qualifier ('primary') front-loaded. It is efficient, though its brevity reflects under-specification rather than disciplined economy.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
With no output schema and no parameter schema, the description carries the full burden of conveying the result shape, yet it says nothing about what fields the returned device contains or how 'primary' is determined. For a zero-argument read tool this leaves the agent unable to predict the response.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
The tool takes zero parameters, so there is no parameter semantics for the description to explain. Baseline 4 applies since the description cannot add or omit parameter meaning.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description names the resource ('the account's primary training device'), which does distinguish it from the broad sibling get_devices by implying a single, default device. However, it is a noun fragment that largely restates the tool name rather than stating a verb+resource action, and it never clarifies what 'primary' means or what attributes are returned.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
There is no when-to-use guidance at all. With siblings like get_devices, get_device_last_used, and get_device_settings, an agent gets no signal about when this single-device lookup is preferred over the general device listing.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.