get_heart_rate_zones

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds only that the result is scoped to the 'current user' (implying no user parameter / auth-derived identity), but says nothing about whether zones are user-configured or computed, caching, or rate limits.

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 restates the same fact twice ('心率区间' and 'Return the current user's heart rate zones'), and the note about one-to-one correspondence with the official client adds no actionable information for an agent. It is short but not front-loaded or information-dense.

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 is the only place to learn what a 'zone' contains (e.g., zone boundaries in bpm, zone count), and it omits this. For a parameterless read tool with readOnly annotations this is tolerable, but the return shape remains a guess.

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?

Zero parameters gives a baseline of 4, but the description's claim that '参数和日期限制沿用官方接口' (parameters and date limits follow the official interface) implies parameters and date filters that the schema does not contain, which can mislead an agent into looking for them. That inconsistency pulls the score down to 3.

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 a specific resource and scope: 'Return the current user's heart rate zones' — clearly a read of the authenticated user's zone configuration. It does not distinguish itself from nearby siblings such as get_daily_heart_rate or get_daily_hrv, so an agent must infer the difference (zones/thresholds vs. time-series data).

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 call this versus get_daily_heart_rate, get_daily_hrv, or other heart-related siblings. The line '参数和日期限制沿用官方接口' (parameters and date limits follow the official interface) hints at constraints but never states them, and in fact conflicts with an empty schema — leaving the agent with no usable selection criteria.

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