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

With no annotations, the description carries the full behavioral burden and does so well: it discloses registry verification, country-specific availability and error behavior, a cap of up to 5 normalized records, the returned fields, and a credit cost. There is no contradiction and no major unstated behavior for the agent to guess.

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?

The description is generally front-loaded and efficient, opening with the core purpose and then covering country constraints, input, output, and cost. It is slightly repetitive in mentioning the return of legal status before later listing the full returned fields.

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?

For a two-parameter registry-verification tool with no output schema, the description supplies the missing return-value information, record cap, supported-country caveats, error behavior, and cost. An agent has enough context to invoke it correctly without further clarification.

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 both parameters are already documented in the schema with examples and an enum. The description restates that query is a registration number or company name and country selects the registry, but adds no syntax or format details beyond the schema.

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 and resource: verifies a company against its official state registry and returns legal status. This is clearly distinct from sibling tools like verify_vat and enrich_company, and an agent can understand the core operation without opening the schema.

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?

Provides important usage context: France works out of the box, while the UK requires a configured Companies House key and otherwise returns an actionable error. It also notes the cost of 1 credit. However, it does not explicitly say when to choose this over enrich_company or screen_sanctions.

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