garmin_trends

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

No annotations are provided, so the description carries the full behavioral burden, yet it only describes what data is returned. It does not disclose the default time window, how many periods are returned, whether data must be synced first, or any auth/rate-limit behavior, leaving significant gaps for a data-retrieval tool.

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 core purpose is front-loaded in the first sentence, followed by the metric enumeration and the period values. The metric list is long but necessary since it is not in the schema; otherwise there is no wasted prose.

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, return-value details need not be explained, and the parameter values are covered. However, the tool has no date-range parameter, so the description should clarify what time window the trend covers by default, which it omits.

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 0%, but the description compensates strongly: it enumerates all valid metric values (a full enumeration absent from the schema) and specifies the acceptable 'period' values ('week' or 'month'). This adds real semantic meaning beyond the bare string-typed 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 states a specific verb and resource ('Return trend data for a metric aggregated by week or month') and enumerates the supported metrics, so the agent knows exactly what it produces. It does not, however, explicitly differentiate itself from the many metric-specific siblings (garmin_steps, garmin_stress, garmin_hrv), which is left to inference.

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?

Usage is only implied by the phrase 'aggregated by week or month', suggesting this is the tool for rolled-up trends rather than raw daily data. There is no explicit when-to-use, when-not-to-use, or named alternative even though dozens of per-metric siblings exist that an agent could confuse it with.

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