health_get_heart_rate

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

No annotations are present, so the description carries full behavioral burden. It discloses the cache-default behavior, auto-syncing logic, the meaning of the live flag, and the returned daily entry structure with zones. This gives the agent useful expectations 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?

The description is well-organized: a one-line summary, a behavior note, an Args section, and a Returns section. It is compact but every sentence adds useful information without padding.

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?

Given that there is an output schema and three optional parameters, the description provides strong coverage of purpose, parameters, caching behavior, and return shape. It could be slightly stronger by warning about unavailable data or explicitly guiding selection among the many health_get_* sibling tools, but it is largely complete.

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%, but the description compensates fully by explaining start_date, end_date, and live with concrete formats like 'YYYY-MM-DD', 'YYYY-MM', and '30d'. It also explains each parameter's default and the effect of live on cache reads.

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 opens with a specific verb and resource: 'Get daily resting heart rate and heart rate zones.' It explicitly identifies the output granularity and zone breakdown, which distinguishes it from sibling health_get_* tools like health_get_activity or health_get_hrv.

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 provides clear usage context: it reads from cache by default, auto-syncs when stale, and the live parameter can force a fresh API fetch. It does not explicitly name alternatives, but the purpose and cache behavior make the typical use case clear.

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