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

The annotations already declare this as a read-only, idempotent, non-destructive, open-world lookup. The description adds useful behavioral context by naming the ANAF public registry as the source, stating that results are in English, and disclosing that BNR EUR/RON data may be included. It does not address error or not-found behavior, but the annotation coverage lowers that burden.

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 a single front-loaded sentence that covers input, source, and returned data without waste. Every clause contributes to understanding what the tool does.

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 simple two-parameter read-only lookup with full schema coverage and rich annotations, the description is complete enough. Since there is no output schema, it helpfully enumerates the returned fields, and no critical calling information appears missing.

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 both parameters are already documented in the schema. The description reinforces that CUI/CIF may be optionally prefixed with RO and that include_fx relates to the BNR EUR/RON rate, but adds no syntax or edge-case 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?

The description states a specific verb and resource: look up a Romanian company by CUI/CIF and return ANAF registry data. It clearly enumerates the returned fields, though it does not explicitly distinguish itself from sibling tools such as get_company_financials or get_company_representatives.

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?

Usage is implied by the input format and returned data: use this when you have a Romanian CUI/CIF and need core company registry information. However, it gives no explicit exclusions, prerequisites, or directions to alternatives like check_identifier_format or get_company_financials.

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