Retrieve a client's cardio and aerobic metrics, including resting heart rate, HRV, VO2 max, blood pressure, and aerobic capacity, for a specified period.
Cardio + aerobic metrics (same physiological domain).
Args: metric: If omitted, returns all supported metrics.
| Name | Required | Description | Default |
|---|---|---|---|
| metric | No | ||
| end_date | No | ||
| client_id | Yes | ||
| start_date | No |
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are supplied, so the description carries the full behavioral burden, and it does not state whether this is read-only, whether client_id implies authorization scoping, what the default date window is, or whether data is paginated. The parenthetical about 'same physiological domain' hints at grouping but discloses no operational behavior.
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?
It is short and front-loaded, with no filler sentences, but the brevity is under-specification rather than efficiency for a four-parameter tool. The parenthetical 'same physiological domain' is vague context rather than an actionable constraint.
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?
An output schema exists, so return values need not be described, but the description leaves the required client_id and both date parameters unexplained and provides no behavioral notes for a data-retrieval tool with zero annotation coverage. An agent would be guessing about the time window and date format.
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%, so the description must compensate, yet it only explains one of four parameters (metric and its omission default). start_date, end_date, and the required client_id are left entirely undefined, including formats and whether dates are inclusive.
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 the resource ('Cardio + aerobic metrics') but is a bare noun phrase with no verb, so the agent infers retrieval rather than being told. Sibling tools are domain-named (get_sleep_data, get_nutrition_data), so the domain framing does implicitly differentiate, but the phrasing itself never states the operation.
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 only guidance given is that omitting metric returns all supported metrics, which is a parameter default rather than a when-to-use rule. There is no direction on when to call this versus get_fitness_assessment, get_healthspan_domain_summary, or get_trends, and no mention of the time-window parameters.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.