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

With no annotations, the description carries the full burden and does disclose the data source, license (CC BY 3.0 AU), cost ($0.02 USDC) and the exact fields returned. It does not say what happens when neither identifier is supplied (0 required params) or what happens if both are supplied, nor error behavior for an invalid ACN/ABN.

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 the use case and identifier formats, then fields, provenance, price, and related tools; no wasted sentences. Minor friction from mixing endpoint-style shorthand ("/registry-batch", "/sanctions") with the real sibling names registry_batch and sanctions_screen.

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?

No output schema exists, so listing the returned attributes is essential and is done here, along with source and pricing an agent needs before spending $0.02. The one meaningful hole is behavior with zero or two identifiers given, against a schema with no required fields.

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 0%, so the description must supply meaning, and it does: ACN is 9 digits, ABN is 11 digits, which is real formatting constraint not present in the schema. It leaves optionality and ACN-vs-ABN precedence unstated, so it doesn't fully close the 0%-coverage gap.

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+resource (Australian company lookup from the ASIC register) and pins down the identifier formats (ACN 9 digits, ABN 11 digits), which cleanly separates it from uk_company, ca_company and company_full. It also enumerates the returned fields (name, former names, type, class, status, dates).

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?

"Use this for..." gives an affirmative use case, and the Related clause explicitly routes bulk work to registry_batch (<=25 UK+AU+CA ids) and screening to sanctions_screen. No explicit exclusion for name-only searches (e.g. company_research/kyb_report), which keeps it short of a 5.

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