get_daily_hrv

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

The annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds that the tool returns both a summary and readings, which is useful return-content information. However, the claim that date limits follow the official interface names a constraint without specifying it, which adds less confidence than a concrete rule would.

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 short by design, but it wastes space: '单日 HRV' restates the tool name, and the 'one-to-one correspondence with the official client' claim conveys no actionable information. The useful English sentence about returning the summary and readings comes last, not first, which puts the description in the wrong order.

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?

Because the tool is simple (one parameter, read-only, no output schema), it does not need a long description. Still, the agent is left without the date format and the actual date-window restriction that the description itself raises, which are the two things most likely to cause a failed call.

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 must carry the whole burden for calendar_date. It only says 'for a calendar date' and gestures at unspecified date limits; it never gives the format (ISO 8601? epoch?), the timezone, or whether future dates are rejected. It leaves the one required parameter essentially undocumented.

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 names a specific verb and resource: it returns HRV summary and readings for a single calendar date. That is clear enough for an agent to act. However, it never distinguishes itself from the sibling get_daily_hrv_summaries, which also appears daily and covers the HRV area, so how the two differ remains a question.

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 says '参数和日期限制沿用官方接口' (parameters and date limits follow the official interface), but it never states an actual rule: it does not say which dates are allowed, whether today's date is allowed, or when to call this tool instead of get_daily_hrv_summaries or get_daily_heart_rate. It points to a rule without stating it, so the agent must guess.

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