health_report

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

With no annotations, the description carries the full burden. It discloses a key behavioral trait: the reply states which window was used and why, prompting verification against the requested range. It also clarifies window semantics (inclusive endpoints, relative length), though detailed parameter logic is covered in the schema. It does not mention permissions, rate limits, or error handling, but for a read-only summary tool this is reasonable.

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 compact (two sentences) and front-loaded with the core purpose. Every sentence earns its place: the first identifies the tool's function and scope, the second explains window behavior and directs to the alternative tool. No fluff or repetition of schema details.

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 the moderate complexity (3 optional attributes, full schema documentation, no output schema), the description is complete enough. It states what the tool does, how the window works, what to verify in the response, and when to use a sibling tool. It conveys essential information for correct selection and invocation without needing to list return fields explicitly.

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%, so the schema already documents all parameters thoroughly. The description adds only minimal extra meaning by framing the window as 'named relative period or explicit dates' and noting that the reply includes the window actually used. This is useful context but does not significantly enhance the parameter semantics beyond the schema.

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 tool generates a summary across multiple health metric domains (heart rate, sleep, activity, blood oxygen, workouts, CPAP therapy), identifying a specific verb and resource. It distinguishes itself from sibling health_query by scope, noting it handles broad summaries while health_query is for anything more specific.

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 explicitly names health_query as the alternative for more specific needs, providing a clear when-to-use boundary. It also explains the window selection logic (named relative period or explicit dates) and instructs the agent to verify period.start and period.end in the reply, giving actionable guidance.

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