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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds real substance beyond that: the returned fields (dwelling count, area, band), the fact that values are per mesh block, and the deliberate exclusion of polygons. It does not discuss result size or how many mesh blocks a suburb may contain.

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?

Three tight sentences with no filler, every one carrying information (report placement, metric definition, geometry pointer). The lead sentence orients to the report UI before stating the data, so the core purpose is not quite front-loaded.

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 does a fair job describing the returned payload (mesh-block rows with count, area and band) and cross-references the geometry and suburb-wide endpoints. The unresolved gap is the input: nothing tells an agent what a valid suburb_name looks like, which is the one thing needed to actually invoke the tool.

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?

There is one required parameter, suburb_name, with 0% schema description coverage, and the description says nothing about its expected format, whether a postcode or state qualifier is needed, or how ambiguous suburb names resolve. The name is largely self-evident, but with no schema help the description should have compensated and does not.

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 (dwellings per km² for every mesh block in a suburb) plus the derived Low → Very high band, and explicitly distinguishes itself from the polygon layer by saying values only, polygons come from /shapes/mesh-blocks. It also implicitly separates itself from the suburb-wide figure at /development/density.

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 places the tool in context ('shown in the suburb report as the Density map layer in the Development section') and redirects the agent elsewhere for geometry ('polygons come from /shapes/mesh-blocks'), which is a clear alternative. It never states when not to use it or when the non-map density endpoint is preferable, so it stops short of explicit routing.

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