Garmin account

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

Annotations already mark the tool as read-only and open-world. The description adds the meaningful detail that the tool returns both the signed-in account and unit preferences. It does not contradict the safe read-only behavior implied by annotations.

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?

The description is a single, efficient sentence with no filler. It front-loads the primary purpose and adds the useful secondary output detail ('unit preferences') in a compact way.

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?

For a no-parameter identity lookup with read-only annotations and an output schema, the description is sufficient. It tells the agent exactly what information the tool provides, and nothing else is required to invoke it correctly.

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?

There are zero parameters and the schema coverage is 100%, so there is no parameter documentation burden for the description. The description fully covers what the tool does without needing parameter elaboration.

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 clearly states the verb 'Identify' and the resource: the signed-in Garmin account plus its unit preferences. It is immediately distinguishable from all sibling tools, which focus on activities, metrics, workouts, and so on.

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?

The intended usage is clear: use this tool when you need to know the currently signed-in Garmin account or its unit preferences. It does not explicitly name alternatives or exclusions, but among the sibling list this tool is uniquely self-describing as an identity/account tool.

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