get_device_last_used

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

With no annotations, the description carries full responsibility but only states the action. It doesn't disclose what happens if no device is last used, whether the data is cached, or any rate limits. However, the simple nature of the tool partially mitigates this gap.

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 extremely concise with a single sentence. While it avoids verbosity, it could be slightly expanded to include usage context without becoming lengthy.

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?

The description is adequate for a simple parameterless tool but lacks details on return format, edge cases (e.g., no device history), and how 'last used' is defined. The absence of an output schema increases the need for such context.

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, so the baseline is 4. The description does not add parameter-specific information, but none is needed as the schema covers 100% of (non-existent) parameters.

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 'Get the last used Garmin device info' clearly states the action (get) and the specific resource (last used Garmin device info). It distinguishes from sibling tools like get_devices (list all devices) and get_primary_training_device (primary device) by targeting the last used device.

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?

No guidance is provided on when to use this tool versus alternatives such as get_devices or get_primary_training_device. Given the large number of sibling tools, explicit context for selection would be valuable.

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