Retrieve daily physiological cycles with strain, kilojoules, and heart rate data. Filter by date range and limit results.
Get WHOOP physiological cycles (days) with day strain, kilojoules, and heart rate summary.
| Name | Required | Description | Default |
|---|---|---|---|
| limit | No | Number of records to return (default 5, max 25) | |
| end_date | No | ISO 8601 end date filter | |
| start_date | No | ISO 8601 start date filter |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the behavioral burden and does indicate a read-only intent through 'Get'. It names the returned metrics but does not disclose pagination behavior, authentication needs, date-range semantics, or any constraints beyond what the schema already states.
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 efficient sentence with the operation, resource, and key output fields front-loaded. No filler or redundant explanation of sibling tools.
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?
The tool has three optional parameters and no output schema, so the description must partially explain returns; it lists day strain, kilojoules, and heart rate summary. However, it does not clarify default limit behavior, what a full cycle record looks like, or when date filters are best used, leaving moderate gaps.
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%, so the baseline is 3. The description adds no parameter-level meaning beyond what the schema already documents, though the 'cycles (days)' phrasing helps clarify the domain of the date filters.
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?
Names a specific verb/resource: 'Get WHOOP physiological cycles (days)', with the parenthetical clarifying cycles are daily periods. Lists distinguishing fields like day strain, kilojoules, and heart rate summary, which differentiates it from sibling tools like get_sleep or get_workouts.
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 gives no explicit guidance on when to use this tool versus alternatives such as get_recovery, get_sleep, or get_workouts. There are no when/when-not conditions or context hints beyond the noun 'cycles', leaving the agent to infer the appropriate use case.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.