Get Garmin HRV

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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false, so the tool's safety profile is covered. The description adds the specific context of 'Garmin Connect China', which scopes the data source geographically, and the date format expectation. However, it does not disclose any additional behavioral traits such as pagination, rate limits, or error semantics, so it only partially augments the 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, efficient sentence that states the resource and the date format upfront. It contains no redundant words or filler, and the essential information is front-loaded. Every word earns its place.

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?

For a simple read-only tool with one parameter and an output schema, the description is largely sufficient. It identifies the data source (Garmin Connect China) and the expected date format. It does not describe the output shape, but the presence of an output schema covers that. A slight gap exists in not clarifying whether the data is for a single day or a range, but the wording 'for YYYY-MM-DD' implies a single day, which is acceptable.

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?

The input schema has zero description coverage for the 'date' parameter, so the description must compensate. It specifies the exact format 'YYYY-MM-DD', which is essential information for correct invocation. While it doesn't mention constraints like valid ranges or timezone, the format guidance is meaningful and directly addresses the documentation gap.

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', the resource 'Garmin Connect China heart-rate variability data', and the expected date format 'YYYY-MM-DD'. It is unambiguous and distinct from sibling tools that target other metrics (sleep, heart rate, etc.). The purpose is immediately apparent.

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 explicit guidance on when to use this tool versus its siblings. It does not mention prerequisites, exclusions, or alternative tools. While the name and purpose imply it is the correct tool for HRV data, the description itself does not articulate any usage context or boundary conditions.

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