Garmin HRV

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

Annotations already declare readOnlyHint, idempotentHint, and openWorldHint. The description adds value by noting that data is returned only when available ('when available') and specifies it is overnight HRV metrics, which are behavioral traits beyond annotations. No contradictions with 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, front-loaded sentence plus a brief disclaimer, with no wasted words. It efficiently conveys the core purpose and constraints.

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?

Given the presence of an output schema (which covers return values), the description is sufficiently complete. It mentions the key behavioral trait (data availability) and the specific metric type (overnight HRV). Minor gaps like prerequisites are not critical, as sibling tools handle connectivity.

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?

Schema description coverage is 67% (2 of 3 parameters have descriptions). The description does not add meaning beyond the schema; it simply ties parameters together. Baseline is 3, and credit is not given for redundant info.

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 'Get' and the specific resource 'Garmin HRV status and overnight HRV metrics' with a scope 'for a date when available', distinguishing it from sibling tools that focus on other metrics. The disclaimer 'Not medical advice' adds clarity.

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 description provides no guidance on when to use this tool versus alternatives like garmin_get_heart_day or garmin_get_sleep_day. It only states 'when available', which implies data existence but does not offer explicit when-to-use or when-not-to-use instructions.

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