garmin_hrv

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

Annotations already establish that this is a safe read operation, so the bar is lower, and the description still adds real behavioral detail: the unit is milliseconds, dates are inclusive, and the window defaults to 7 days and is capped at 90. It does not describe pagination or how much data is returned for a 90-day request, though the output schema covers the shape.

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 sentences with no filler, and the most important information (what is returned and in what unit) is front-loaded before the date-range constraints. Every clause carries information the schema does not.

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, the description needn't explain return values, and the annotations already cover the safety profile, so the remaining burden is the date-range semantics, which it handles. The only meaningful gap is that it doesn't clarify how this differs from the two HRV sibling tools.

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%; the parameters are bare "Start" and "End" fields with no format hints. The description compensates well by establishing that these are inclusive wake-up dates with a 7-day default and a 90-day maximum. It falls short of 5 because the accepted date string format (for example YYYY-MM-DD) is still left to inference.

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?

States a specific resource and the values returned: nightly HRV, weekly average in milliseconds, Garmin baseline and status. It does not, however, distinguish itself from the sibling tools garmin_api_hrv_daily and garmin_api_hrv_summaries, so an agent cannot tell from the description alone which of the three to pick.

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 default window (last 7 days) and the 90-day cap imply how the tool is normally called, which is useful context for choosing it. But there is no explicit statement of when to use this tool rather than the hrv_daily or hrv_summaries siblings, and no exclusions or prerequisites.

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