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

Annotations already cover readOnly, idempotent, and non-destructive hints. The description adds critical context beyond annotations: pricing ($0.005 per call via x402 on Base), that unknown numbers return 'not_found' and are not charged, that failed calls are not charged, and the fallback behavior for clients without x402 support. This is excellent disclosure of non-obvious operational traits.

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 return contents, then sourcing guidance, then pricing/behavioral details. Every sentence earns its place with no redundancy. Well-structured and appropriately sized for the information density.

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?

Given the presence of an output schema (so return values need not be explained in detail), the description goes beyond by enumerating key fields returned, covering error cases, pricing, and data source attribution. Complete for a single-parameter getter with rich annotations.

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% and the parameter's schema description already provides the example format. The description restates that the parameter is 'Planning Portal CDC number' but adds no syntax or format details beyond what the schema provides. Baseline 3 is appropriate.

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 ('Get the full record'), resource ('NSW complying development certificates'), and identifier ('Planning Portal CDC number'). Clearly distinguishes from sibling nsw_cdc_get_summary by emphasizing 'full record' and enumerating the fields returned.

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?

Explicitly tells the agent where to get valid CDC numbers ('Take CDC numbers from search_applications or search_nearby_applications'), which is the key precondition. Also specifies behavior for unknown numbers. No ambiguity about when to use this vs alternatives.

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