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

Annotations already declare readOnly/idempotent/non-destructive/closed-world, and the description goes well beyond them: 100-result cap per call, has_more/offset paging, $0.01 per-call cost paid via x402 in USDC on Base, the failure mode for non-x402 clients (payment requirements returned as an error result), and that failed calls are not charged. That is exactly the kind of cost, auth and error behavior annotations cannot express.

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?

Opens with purpose and scope, then results shape, then filter constraints, then routing, then billing, then provenance. Every sentence carries distinct operational information (paging, cost, payment fallback, licensing) with no filler or repetition of the title/schema.

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 an output schema present and full schema coverage, the description still usefully sketches the result fields and paging, plus billing, error behavior and data provenance. Nothing needed to decide whether and how to call this tool is missing.

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 description coverage is 100%, so per-parameter meanings are already documented and the baseline would be 3. The description adds a constraint not present in the schema — that four filter parameters are only valid in combination with a location parameter — which is genuine added semantic value.

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 (Search) plus resource (NSW complying development certificates) with an explicit scope line (council, suburb, postcode, lodgement date) and ordering (newest lodgement first). It also names the sibling to use for the full record (get_application), so an agent can distinguish it from nsw_cdc_get_application and nsw_cdc_nearby_applications.

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 an explicit combining rule — status, application_type, development_type and min_cost must be paired with council, suburb or postcode — and routes to get_application for full records. It does not say when to prefer nsw_cdc_nearby_applications or nsw_cdc_summary over this tool, so one sibling choice is left to inference.

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