eu-company-mcp-server

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

Discloses critical behavioral limitation (Germany never returns name/address, others do) and data source, though lacks rate limit or auth details.

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?

Well-structured with purpose front-loaded; Args section is clearly delineated, though labels like 'Hinweis:' and 'Quelle:' add slight verbosity.

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?

Adequately covers expected return values (validity status, optional name/address) and limitations despite absence of output schema.

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?

Excellent compensation for 0% schema coverage: provides clear format specifications and concrete examples for both parameters (especially the no-prefix requirement for vat_number).

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?

Clear specific purpose (validate EU VAT IDs) with resource identification (EU VIES System) and distinguishes from company lookup siblings.

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 through functionality description (validating VAT IDs), but lacks explicit when-not-to-use guidance or comparison to company search alternatives.

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