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

Annotations already declare readOnly/idempotent/openWorld/non-destructive, and the description goes beyond them by disclosing the pricing model and access method ('$0.005 per call (x402, USDC on Base, no account)'), which is material for calling the tool at all. It does not add rate limits or error/edge behavior, keeping it short of a 5.

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-loads cost, then the when-to-use clause, then the returned-field inventory in a single tight paragraph with no filler. The field list is dense but each item is a distinct queryable attribute, so little text is wasted.

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 an output schema present, return values need not be explained, and the description correctly covers cost, input source, and scope for a read-only lookup. The only gap is sibling routing, since it never says how this profile differs from the full-report or KYB variants.

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?

Only one parameter, and the schema description already covers it fully at 100% coverage, including the CUI format and the pointer to romania_company_search. The description only echoes the identifier ('by CUI/CIF') without adding format or validation detail, so the baseline 3 for schema-carried semantics is correct.

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 ('Romanian company profile and VAT check by CUI/CIF') and enumerates the exact fields returned: legal name, ONRC status, legal form, CAEN, ANAF VAT payer flags, administrators. It clearly differs from a search tool, but does not distinguish itself from near-siblings such as romania_company_full_report or romania_company_risk_kyb, which likely overlap.

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 when you need invoicing data, VAT status, legal form or who runs a known Romanian company' gives clear activation context and implies the company must be known (CUI in hand). However, it names no exclusions or alternatives among the seven siblings, so an agent cannot tell why to pick this over romania_company_full_report.

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