Get WHOOP cycle by ID

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

No annotations are provided, so the description carries the full burden of behavioral disclosure, and it discloses almost nothing. It does not state that this is a read-only fetch, whether authentication is required, whether the result can be empty for an unknown id, or any scoping behavior. Being a plain noun phrase, it adds no behavioral context beyond the schema.

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 front-loaded sentence fragment with zero filler. It is efficient, though it is a fragment rather than a well-formed instruction, which keeps it short of a 5.

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 an output schema present, return-format explanation is unnecessary, and the sole parameter is fully covered by the schema. What is missing is the relationship to get_cycles and any note on what 'physiological cycle' returns, leaving a minimal-but-usable definition.

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%: cycle_id is documented in the schema with type and an example origin ('from get_cycles or a recovery record'). The description adds nothing beyond that, so the baseline of 3 for schema-covered parameters applies.

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 phrase 'A single physiological cycle by its numeric id' identifies the resource and implies a fetch-by-key, but supplies no verb (get/fetch/retrieve) and never names the sibling get_cycles it contrasts with. An agent can infer it is a single-record lookup versus the list tool, but must infer rather than read it.

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?

There is no when-to-use guidance, no prerequisites, and no mention of alternatives such as get_cycles. The only implied routing signal is 'single ... by its numeric id', which the agent must extrapolate on its own.

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