get_resting_heart_rate

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

No annotations are provided, so the description carries the full behavioral burden. It usefully discloses that results include 7-day and 30-day trend summaries (not just raw daily values), but it says nothing about permissions, rate limits, or whether trends are returned even when a shorter window is requested. As a read-only metric fetch the risk is low, so a 3 is fair.

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?

One compact sentence that front-loads the core resource and immediately follows with the aggregation scope and cap. Every clause carries information; nothing is padded or repeated.

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 need not explain return values, and the single optional parameter is fully covered by the schema. The only material gap is the absence of sibling-differentiation guidance against get_health_summary/get_full_snapshot, which leaves tool selection partly ambiguous.

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 100% — the single 'days' parameter is fully documented with a default of 30 and a max of 30. The phrase 'up to 30 days' echoes that constraint but adds no new syntax or format meaning, so the baseline 3 applies.

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 names a specific metric (resting heart rate) and the aggregation it returns (daily values plus 7-day and 30-day trend summaries), which is a clear verb+resource statement. It does not, however, distinguish itself from metric-adjacent siblings like get_health_summary or get_full_snapshot, so an agent must infer the boundary.

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 when-to-use or when-not-to-use guidance and no mention of alternatives such as get_health_summary or get_full_snapshot, which could also surface heart-rate data. The agent receives no routing signal for choosing this tool over its many siblings.

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