garmin_trends

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

Annotations already declare readOnly, idempotent, and open-world behavior, so the safety profile is covered. The description adds genuinely new behavioral context beyond that: the result set is small, aggregation is bucketed, and the lookback horizon spans 12 weeks by default up to two years. It does not discuss data latency or empty-period behavior, which keeps it short of a 5.

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?

One dense sentence plus a short usage clause; the purpose and metric scope are front-loaded, and the long metric list is justified because it defines the tool's coverage. There is no filler or repetition of annotation data.

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 tool has a full output schema and complete annotation coverage, so the description's job is to convey purpose, scope, and usage, all of which it does. Nothing an agent needs in order to call this correctly (defaults, granularity, span limits) is missing between description and schema.

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 100%, with each of the three parameters documented inline including defaults and valid ranges. The description reinforces the default (12 weeks) and the upper bound (2 years) but adds no formatting or interpretation details beyond the schema, so it sits at the baseline.

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 concrete operation (weekly/monthly averages over a long period) and enumerates the exact resources covered (resting HR, HRV, sleep, steps, stress, Body Battery, intensity minutes, workouts, training load, weight). It also distinguishes itself from the daily-detail siblings by explicitly framing its role as 'progress and long-term patterns' with 'small output', so an agent can tell it apart from garmin_daily_summary or garmin_heart_rate without opening schemas.

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?

It gives a clear use case: 'use it for progress and long-term patterns', with the supporting signal that output is small. However, it never explicitly names when NOT to use it or points to a specific sibling (e.g., use garmin_daily_summary for a single day), leaving that inference to the agent.

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