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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, not open-world), and the description adds genuinely new context: the reporting window (latest month plus same month a year earlier), the exact measures returned, and that it is free to use. It does not discuss pagination or response shape, but for a read-only public dataset that is a minor omission.

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 the data content, then the usage trigger, then the minimal call instruction and cost note — every clause carries information. The tail ('Give specialty and/or district. Free.') is slightly clipped but not wasteful.

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?

There is no output schema, but the description compensates by stating exactly which measures and which time periods come back, and the schema thoroughly documents both optional filters. An agent has what it needs to decide and invoke; only return formatting/pagination remains unstated.

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 the two parameters' matching, stemming and alias behavior is already fully documented in the schema. The description only adds that both are optional and combinable ('Give specialty and/or district'), which is a valid but marginal addition over the structured data, so the baseline 3 applies.

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 the exact resource (Health NZ public-system waiting lists) and enumerates the metrics returned: people waiting for a first specialist assessment, for planned treatment, and the share waiting over 120 days, plus the two-month time window. It is unmistakably distinct from the doctor/practice siblings, though it never names or contrasts them explicitly.

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?

'Use it when the person is weighing public against private, or which district is faster' gives a concrete situation that selects this tool, and 'Give specialty and/or district' tells the agent how to scope the call. No explicit exclusions or named alternatives against the sibling tools, so it stops short of a 5.

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