Get WHOOP cycles

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the full burden and does disclose non-obvious behavior: reverse-chronological ordering, that the current cycle has no `end`, and that the range is matched against the activity's own start/end window rather than the wall-clock query window. It omits auth needs and rate-limit behavior, keeping it short of a 5.

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?

Three tight sentences: resource definition and ordering first, field meanings second, selection/pagination mechanics third. No filler and the most important orientation (what a cycle is) is front-loaded.

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 structure need not be restated, yet the description still supplies enough domain framing (cycle boundaries, current-cycle null end, field semantics, pagination) for an agent to call it correctly. Nothing critical is missing.

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 coverage is 100%, so the baseline is 3. The description goes beyond the schema by explaining what the returned cycle fields mean (score.strain = day strain 0-21, kilojoule = energy burned), defining cycle boundaries, and clarifying the range-matching semantics that the schema does not state.

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?

States the specific resource (physiological cycles, one per WHOOP day from wake-up to wake-up) and the ordering (newest first), which is a clear verb+resource framing. It implicitly distinguishes itself from get_cycle_by_id (list vs single), but never names that sibling explicitly.

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?

Gives operational guidance on parameters ('Use start/end to select a date range and next_token to page'), but says nothing about when to prefer this list tool over get_cycle_by_id or get_sleep_for_cycle/get_recovery_for_cycle, which are the real routing alternatives among the siblings.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.