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

Annotations (readOnlyHint=true, idempotentHint=true, openWorldHint=false) already declare this is a safe, repeatable, closed-world read. The description adds value by listing the returned data fields, which matters because there is no output schema. It still omits behavioral context like whether missing companies return null vs error, or whether the lookup is live vs cached.

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-loading 'Returns ...' is good, but the payload is a raw comma-dumped field list with inconsistent formatting (a trailing space before 'Args:') rather than a structured, scannable breakdown. It is moderately verbose without clear hierarchy.

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, listing returned fields is a reasonable compensation. But the omission of any differentiation from the many sibling company-lookup tools (WW_start, WW_advanced, EU_*, IT_*) leaves a material gap for correct tool selection.

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 0%, so the description carries the burden and does map both parameters (vat_or_taxCode = VAT or tax code; country_code = country code). But it adds no format syntax, casing, or example values, and does not clarify the interaction between the two required args.

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 states a clear verb ('Returns') and enumerates the resource fields for a worldwide company lookup, so the agent knows what data comes back. However, it never distinguishes this tool from its close siblings get_company_WW_start and get_company_WW_advanced (nor the EU/IT variants), and the title ('Start...') even conflicts with the name ('top'). An agent cannot tell from the description which WW tier to pick.

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?

There is no when-to-use guidance, no mention of what makes this the 'top' tier versus 'start' or 'advanced', and no prerequisites (e.g. which VAT/taxCode formats are accepted, or coverage limits). Usage must be entirely inferred from the name.

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