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

Annotations already mark this read-only, idempotent and non-destructive, yet the description adds substantial context beyond them: result caps (10 of each, nearest first), default and max radius, error-with-suggestions behavior for unknown addresses, the $0.05 x402/USDC-on-Base payment flow including what happens to non-x402 clients, and a not-charged guarantee for failed calls.

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 purpose, then inputs, then outputs, then cost and exclusions — a sensible order with no filler sentences. The data-source/licence tail is long but arguably necessary for attribution; still, the block is dense and would read better split into short sentences or a list.

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 paid, multi-source aggregate tool this covers everything an agent needs: what comes back, result limits, coverage gaps (no DCP controls), failure modes with billing implications, and payment mechanics. An output schema exists, so the description need not detail field shapes, and it correctly avoids doing so.

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 baseline is 3, but the description adds the either/or relationship between address and lat/lng that the schema does not express, plus the default/max semantics for radius_m. It does not clarify what happens if both address and coordinates are supplied.

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 specific verb and resource (get planning controls, lot and development applications) for a NSW address, and the 'in one call' framing distinguishes it from the per-record siblings like nsw_da_get_application and nsw_cdc_get_summary. The enumeration of returned control types makes the scope unmistakable.

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 concrete input guidance (pass address OR lat/lng, with an example) and an explicit exclusion: 'Council DCP controls such as setbacks are not included.' It stops short of naming the sibling tools an agent should fall back on for DA-level or CDC-level detail, so routing is implied rather than spelled out.

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