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

With no annotations, the description carries the behavioral disclosure burden, and it does so well: it reveals the decimal-fraction output format, the suburb-wide aggregation level, the property-type breakdown, and the map-surface alternative. It omits data vintage or response wrapping, but the output schema covers the return shape.

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 two sentences with no redundancy. The core metric and unit are front-loaded, and the alternative tool is presented in a short, unambiguous second sentence.

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?

For a single-parameter, read-style metric with an output schema present, the description provides the key decision context and output interpretation. The only notable omission is explicit parameter-format guidance, which is partially mitigated by the descriptive parameter name.

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?

The schema has no description for `suburb_name`, so the description is the only source of parameter context. The 'Suburb-wide' phrasing does tie the lone parameter to the intended geography, and the parameter name is self-describing, but there is no guidance on accepted name formats or normalization. This is a moderate gap rather than a failure.

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 identifies a precise metric: 'Suburb-wide rental vacancy rate by property type,' and specifies the output unit with a concrete decimal-fraction example. It also distinguishes itself from the per-mesh-block map surface, though it does not explicitly contrast with the rate-series sibling or use a clear verb like 'returns.'

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 gives an explicit decision branch: use `/market/vacancy-map` for the per-mesh-block surface, implying this tool is for suburb-wide granularity. It does not mention alternatives such as the vacancy-rate series, so the guidance is clear but not exhaustive.

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