Health profile

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

Annotations already cover readOnly/idempotent/non-destructive/closed-world, yet the description adds substantial behavior the structured fields cannot: every field may be null, `profile` is null when nothing was uploaded, the reply's `note` explains why, nulls must never be guessed, and the row is replaced in place so there is no upload timestamp indicating currency. It even clarifies that a profile is not a series and `coverage.days_covered` is 0 by construction.

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 purpose and the pre-requisite use case are front-loaded in the first two paragraphs, and each subsequent sentence carries a distinct constraint (null handling, no partner, non-series semantics, no upload time). No filler or restatement of the name.

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 an output schema present and no nested objects, the description need not describe return shapes, yet it still pre-empts the two most likely agent errors: treating a profile like a time series and hallucinating values for null fields. Nothing needed to call it correctly is missing.

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% and the sole parameter `fresh` is never mentioned, let alone explained (is it a cache bypass? a re-read?). The description compensates richly for output semantics but leaves the one input entirely undocumented, which is the reverse of what a low-coverage schema requires.

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 precise verb and resource ("Read YOUR health profile") and enumerates the exact fields returned: biological sex, age, date of birth, height. It also differentiates from siblings that take a partner option by asserting this tool has none, so the agent can place it relative to get_metric/get_symptoms without opening a schema.

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?

Gives an explicit use condition: call it before anything depending on sex, age or height (BMR, HR zones, VO2 max bands, BMI). It also states a constraint (no partner option), which functions as a when-not. It stops short of naming a sibling alternative or a case where a different profile-ish tool should be preferred.

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