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

Annotations already declare readOnlyHint=true, idempotentHint=true, and openWorldHint=false, so the safety profile is covered. The description adds the returned field list (companyName, vatCode, address, activityStatus), but says nothing about auth, rate limits, or what happens when a company is not found.

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 purpose, then return fields, then args. The 'Returns:' and 'Args:' blocks are efficient, though the repeated 'Returns' phrasing is slightly redundant.

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 return fields is the right move, and both required params are exemplified. However, the missing when-to-use guidance against the many company siblings leaves a real gap for an agent choosing among alternatives.

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 carries the full burden and mostly delivers: it gives concrete vatCode examples (DE123456789, FR12345678901234), clarifies vatCode may be a registration number, and shows the country_code format and accepted values. It stops short of stating format/length constraints per country.

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 (Returns) and resource (basic company information) scoped to a specified country. The word 'basic' implicitly contrasts with the 'advanced' sibling variants, but the description never names or explains that contrast, so the differentiation is only partial.

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?

No guidance on when to prefer this over get_company_EU_advanced, get_company_WW_start, or the other ~20 company siblings. The agent must infer from the name alone that 'start' means a lightweight lookup.

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