get_cycleFetch a specific WHOOP physiological cycle by ID, returning its recovery and main sleep details.
One physiological cycle by id, together with its recovery and main sleep.
| Name | Required | Description | Default |
|---|---|---|---|
| raw | No | Return WHOOP's raw API objects instead of compact summaries with friendly units. | |
| cycle_id | Yes | Cycle id (from list_cycles or get_daily_overview). |
Changes observed during successful MCP inspections.
v1.0.2Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, idempotent, open-world, non-destructive, so safety is covered. The description adds the genuinely useful fact that the response bundles related recovery and main sleep data, but says nothing about the raw flag's effect or behavior for a missing/invalid id.
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?
A single sentence with no filler; the resource and the id scoping are front-loaded before the bundled-data note.
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?
With no output schema, the description usefully signals that recovery and main sleep come back alongside the cycle. Annotations carry the safety profile, so the only real gap is error behavior on an unknown id.
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 both parameters are already documented, including where cycle_id comes from and what raw does. The description adds no additional parameter meaning, making the baseline 3 correct.
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 resource (physiological cycle), the retrieval scope (one, by id), and the payload composition (recovery + main sleep). That distinguishes it from list_cycles and get_sleep/get_recovery without naming them explicitly, so it stops short of a 5.
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?
No statement of when to use this versus list_cycles, get_daily_overview, list_recoveries, or get_sleep. The only routing hint ('from list_cycles or get_daily_overview') lives in the cycle_id schema field, not the description.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.