get_hrv_data

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

The description includes a useful behavioral caveat that return_timeseries can return large data. It is a read-only retrieval tool, so the lack of destructive side effects is evident, but the description does not disclose what the default output contains, how the summary relates to the timeseries, or any rate-limit or unit considerations. Without annotations, the description carries the burden and only partially meets it.

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 concise: a one-line purpose followed by a focused Args list. Every sentence adds useful information, and the most important usage caveat is placed with the relevant parameter.

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?

For a two-parameter tool with an output schema, the description covers the required inputs and the optional behavior well. It does not explicitly state that the timeseries defaults to false, but the schema provides the default, and the output schema reduces the need to describe return values.

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 0%, so the description fully compensates by explaining both parameters. It specifies the required date format (YYYY-MM-DD) and gives the boolean return_timeseries meaningful semantics: include detailed 5-minute HRV readings, with a size warning.

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 the action ('Get') and the resource ('Heart Rate Variability (HRV) data'), so an agent can infer the tool's basic function. It does not explicitly differentiate itself from the related sibling get_hrv_trend, though the mention of per-date data and timeseries readings provides some distinction.

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 guidance on when to use this tool versus alternatives such as get_hrv_trend, get_training_readiness, or get_body_battery. The description only documents parameters and does not mention contexts, exclusions, or preferred alternatives.

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