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

Annotations already declare it as read-only, idempotent, open-world and non-destructive. The description adds valuable operational context: it runs in one call, costs 2 queries, requires Plan Pro, and returns alerts plus a pass/review/fail recommendation.

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 dense but mostly earns its length by covering checks, return values, usage, plan and cost. It is slightly front-loaded into one long Spanish sentence and ends with a redundant English summary line.

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 complex KYB verification tool with no output schema, the description explains what is checked, optional checks, alert behavior and returned fields such as legal form, LEI, parent and sole partner. It also covers cost and plan requirements, leaving no major decision gap for the agent.

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%, so the schema already documents all five parameters. The description maps name, person, vat and eori to their business checks, but adds little syntax or format detail 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 precise verification purpose: KYB onboarding check for a Spanish company, including existence/operation, name match, signer role, optional VIES and EORI checks. It clearly distinguishes itself from the data-lookup sibling get_company.

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 says to use it to decide and to use get_company for data lookup only. It also notes the Plan Pro requirement and query cost, which helps the agent choose correctly.

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