get_heart_rate_trends

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It only says 'Returns' trends, which hints at a read operation, but it does not describe what 'over a time period' means, whether the days parameter is required, what default behavior occurs, or any units or granularity.

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 focused sentence with no wasted words. It is front-loaded with the core output type, though it sacrifices useful detail for brevity.

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 no output schema and no annotations, the description is the only source of context, and it leaves key decisions unclear. An agent cannot confidently determine how to set the days parameter, what the returned trend data looks like, or whether calling without parameters is valid.

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 does not explicitly connect the 'days' parameter to the time period or explain its semantics. The phrase 'over a time period' is vague and does not clarify whether days is optional, what the range is, or what happens when it is omitted.

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 uses a specific verb ('Returns') and a specific resource ('resting, max, and average heart rate trends'), making the tool's function immediately clear. It is distinguishable from sibling tools like get_vo2_max_trends or get_sleep_data because it names heart rate metrics explicitly.

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 implies this tool should be used when heart rate trend data is needed, but it gives no explicit guidance on when to choose it over sibling tools like get_vo2_max_trends or get_recovery_status. There are no exclusions or alternative-routing hints.

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