get_heart_rateRetrieve detailed heart rate data for a specific date, including resting heart rate, maximum heart rate, and time spent in each heart rate zone.
Get detailed heart rate data for a specific date including resting HR, max HR, and HR zones.
| Name | Required | Description | Default |
|---|---|---|---|
| date | No | Date in YYYY-MM-DD format. Defaults to today if not specified. |
Changes observed during successful MCP inspections.
v4.3.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and openWorldHint=true, so the safe-read nature is covered. The description adds value by naming the included measurements, but it does not disclose behavior around missing data, timezone interpretation, or returned structure.
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 sentence, front-loaded with the tool intent, and no filler. The phrase 'including resting HR, max HR, and HR zones' efficiently communicates the scope of returned data.
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 is simple, has one optional date parameter, good annotations, and a clear description of returned data kinds, the information is sufficient. Lack of edge-case details like no-data behavior is a minor gap but not severe.
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%, including the date format and default-to-today behavior. The description only lightly reinforces the date parameter and does not need to add more because the schema already carries the semantics.
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 and resource: get detailed heart rate data for a particular date, listing resting HR, max HR, and HR zones. This clearly differentiates it from related siblings like get_activity_hr_zones and get_rhr_day, which target different scope or data types.
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 use for retrieving date-scoped heart rate details, which is useful context, but it does not explicitly state when to prefer this over sibling tools such as get_rhr_day or get_activity_hr_zones, nor does it mention exclusions.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.