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

Annotations already declare readOnly, idempotent, non-destructive and open-world, so the description is free to add other context — and it does: the upstream source, the coverage limitation (no community infections), and the 1-credit cost. It does not mention reporting lag for weekly NHSN data, which would be the one remaining behavioral caveat worth knowing.

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?

Front-loaded with a plain-language question that immediately frames the purpose, followed by the precise technical statement of what is returned. The audience sentence is slightly promotional but does carry seasonal-usage signal, so little is truly wasted.

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 carries the return-value burden well, enumerating each measure and the national/state split. A note on data lag or the default time window would close the remaining gap for a weekly surveillance series.

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 coverage is 100%, so both parameters are already documented. The description only echoes the jurisdiction dimension ('nationally or for one state') and says nothing about the weeks parameter, its 1-52 range, or the default of 4 — baseline 3 is appropriate.

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 resource and metric: weekly new hospital admissions for laboratory-confirmed RSV, with the exact breakdown (children/adults, in-hospital, ICU, season-to-date) and the source (CDC NHSN). The RSV scope cleanly separates it from the sibling flu_hospital_admissions_weekly and covid_hospital_admissions_weekly tools without needing to name them.

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?

It gives concrete usage context ('parents of infants, paediatric services and reporters each autumn and winter') and an explicit scope exclusion ('Hospital data only; it does not count community infections'). What it lacks is explicit routing to the flu/COVID equivalents or guidance on when a different surveillance tool would be preferable.

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