garmin_get_body_metrics

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the tool's safety profile. The description adds the date-range scope and clarifies data type but does not disclose additional behaviors like caching, rate limits, or data freshness. Some context is added, but not substantially beyond 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 concise sentence of 11 words, front-loaded with the action and resource type. There is no redundancy or filler, and the structure is optimal for a simple read operation.

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 3 parameters and an output schema, and annotations cover safety. The description is adequate for the core purpose but omits usage guidelines, the refresh parameter's meaning, and any differentiation from sibling tools. These gaps make it minimally complete for effective tool invocation.

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%, and the description only implies a date range via 'for a date range'. It does not explain the required start_date and end_date parameters or the optional refresh parameter, which remains ambiguous. The description fails to compensate for the lack of schema descriptions, leaving parameter meaning largely undisclosed.

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 resource 'body composition and blood-pressure data' with a date-range scope. This distinguishes it from sibling Garmin tools like sleep or activity retrieval, though it does not explicitly name alternatives. Purpose is specific, but sibling differentiation is implicit rather than explicit.

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 such as garmin_get_day or garmin_get_trends. It only states what the tool does, with no mention of use cases, exclusions, or preferred scenarios. This leaves the agent without clear decision support for tool selection.

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