garmin_spo2

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

Annotations already provide readOnlyHint=true and openWorldHint=true, covering the safety profile. The description adds the specific returned metrics (average and lowest overnight SpO2), which is useful behavioral context. It does not mention rate limits or permissions, but for a read-only tool with annotations this is acceptable.

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, front-loaded sentence with zero filler. It efficiently conveys the core purpose without redundancy. For a tool with one parameter, this length is appropriate, though it could be slightly more explicit.

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 an output schema present and read-only annotations, the description covers the core domain. However, it omits critical information about how to specify the date parameter (format, optionality, null semantics), which is necessary to invoke the tool correctly. This is a notable gap for such a simple tool.

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 schema has one optional 'date' parameter with no description (0% schema coverage). The description's 'for a day' hints that the parameter specifies the day, but it fails to explain date format, null behavior, or default semantics. This does not adequately compensate for the complete absence of schema documentation.

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 identifies the resource (SpO2 pulse oximetry) and the scope (a day, with average and lowest overnight values). It is distinguishable from sibling tools like garmin_heart_rate or garmin_stress. However, it lacks an explicit verb like 'get' or 'retrieve', making it slightly less direct than ideal.

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, nor are there prerequisites, typical scenarios, or exclusions. The phrase 'for a day' only implies daily usage but does not explicitly route the agent away from other metrics or explain context.

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