query_heart_rate_data

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

The description adds value beyond annotations by specifying the data fields returned (resting HR, average HR, min/max) and query flexibility (single date or range). It is consistent with readOnlyHint and does not contradict annotations, though it could mention pagination or data availability.

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 extremely concise: two short sentences that front-load the core purpose ('Get heart rate data') and immediately provide necessary details. Every word earns its place with no redundancy or filler.

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?

Given the tool's relatively simple nature (4 optional parameters, read-only, existing output schema), the description adequately covers the essential context: what data is retrieved and query modes. It is complete enough for an agent to select and invoke correctly, though it could mention supported date formats or error cases.

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?

With 100% schema description coverage, the baseline is 3. The description does not add new meaning beyond the schema's parameter descriptions; it merely restates the date range support. No additional value is provided for parameters like 'include_resting'.

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 tool's purpose with a specific verb ('Get'), resource ('heart rate data'), and elaborates on what is included (resting HR, average HR, min/max values). It distinguishes from sibling tools (e.g., query_sleep_data) by focusing on heart rate, making selection unambiguous.

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 usage for retrieving heart rate data for single dates or ranges, but provides no explicit guidance on when to use alternatives or when not to use this tool. The context is clear enough, but lacks comparative guidance to avoid misuse.

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