Retrieve your resting heart rate trend for the last specified days (up to 28) to monitor cardiovascular recovery and baseline changes.
Resting heart rate trend over the last days days.
Args: days: How many recent days to include. Capped at 28.
| Name | Required | Description | Default |
|---|---|---|---|
| days | No |
| Name | Required | Description | Default |
|---|---|---|---|
| days | Yes | ||
| avg_rhr_bpm | No |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries full burden for behavioral disclosure. It mentions the cap of 28 days, which is a useful constraint, but does not describe whether the tool is read-only, what side effects exist, or any rate limits. The read-only nature can be inferred from 'get' but is not explicit.
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 exceptionally concise: one sentence stating the purpose, followed by a brief structured Args section. Every word earns its place. No redundant phrases 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 simplicity (single parameter, obvious read operation) and the presence of an output schema, the description is sufficiently complete. It covers the main purpose and the parameter constraint. A minor gap is the lack of detail on trend format, but this is acceptable with an output schema.
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?
Despite the schema having no description for the parameter 'days', the tool description adds a clear explanation: 'How many recent days to include. Capped at 28.' This fully compensates for the missing schema description and provides practical usage 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 clearly states that the tool retrieves the 'resting heart rate trend over the last days.' The verb 'get' and resource 'resting heart rate trend' are specific and distinct from sibling tools like get_hrv_status or get_sleep. No ambiguity.
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 provides no guidance on when to use this tool versus alternatives. It does not mention prerequisites, limitations, or scenarios where another tool would be more appropriate. Contextual usage remains completely implicit.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.