garmin_heart_rate

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

Annotations already declare the operation read-only and open-world, so the safety profile is covered. The description adds a useful detail about what summary and raw return (min/max/resting vs 2-minute series), but does not address default-date behavior or API-level constraints; the bar is lower due to 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?

Two short sentences with no filler; the main scoping phrase comes first and the mode details follow. Every word carries meaning.

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 optional-parameter read with an output schema and read-only annotations, this is close to adequate. The notable gaps are undocumented date semantics and missing guidance on when this tool is preferred over related Garmin metric 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 property descriptions are absent (0% coverage), so the description must help interpret the two parameters. It does clarify that raw selects between summary and raw series, but the date parameter is only weakly tied to 'for a day' with no format, default, or null behavior explained.

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 names the resource (heart rate) and the scoping (a day), and the second sentence distinguishes the summary and raw variants. It is recognizable as the heart-rate metric tool among the many Garmin siblings, though it lacks an explicit verb such as 'retrieves'.

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?

There is no statement about when to use this tool versus garmin_daily_summary or other metric siblings, nor any exclusion criteria. The summary/raw distinction is an output-mode detail, not a tool-selection guideline.

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