garmin_body_battery

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

The annotations already declare this as a read-only, idempotent, non-destructive operation. The description adds useful behavior not in the annotations: a 90-day maximum range and that samples are omitted by default. It does not mention authentication or rate limits, but those are less critical given the annotations and output schema.

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?

Two short sentences, front-loaded with the core purpose and followed by the most important usage distinction. No wasted language.

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 output schema and annotations cover return data and safety behavior, and the description covers date range and sample inclusion adequately. However, for a four-parameter tool with 0% schema description coverage, the unexplained intervals_per_day parameter leaves a clear completeness gap.

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%, so the description must compensate. It clarifies include_samples via the 'samples are omitted' statement and adds a 90-day cap for the date range, but it never explains intervals_per_day, leaving a meaningful parameter undocumented.

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: read Body Battery charged/drained values and optional time series. It also distinguishes this tool from the sibling garmin_daily_summary by reserving daily lowest/highest values for that sibling.

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 explicitly directs the agent to daily_summary for daily lowest/highest values, which is a clear alternative-selection rule. It also notes that samples are omitted by default, but it does not cover when not to use this tool or other relevant sibling distinctions.

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