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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=false, which tell the agent this is a safe, repeatable, limited lookup. The description adds the list of returned fields, which is useful context, but does not describe auth, rate limits, caching, or error behavior. With annotations carrying the safety profile, 3 is appropriate.

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 first sentence is front-loaded and informative, listing the exact returned fields. The 'Args:' block repeats the parameter name and gives a tautological description that adds little. Overall reasonably sized but includes a redundant section.

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 1-param read-only lookup with no output schema, the definition is adequate yet incomplete. It lists returned fields, which is helpful, but lacks format guidance for the input, error semantics, and sibling differentiation. An agent could call it, but might also misroute to a more expensive sibling.

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 0%, and the parameter name 'vat_or_taxCode' is not self-explanatory. The description repeats the one-line arg description but does not explain format (e.g., numeric string, length, optional IT prefix), nor whether vatCode and taxCode are different formats, nor what happens for foreign codes. Since coverage is low, the description must compensate and it does so only minimally.

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 verb+resource: returns company data from a VAT or tax code. But it doesn't distinguish from siblings like get_company_IT_full, get_company_IT_advanced, or get_company_IT_search which sound like they do similar things. Still, 'start' vs 'advanced'/'full' implies a low-fidelity cheap lookup, but this is not stated.

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?

No guidance on when to use this vs get_company_IT_advanced, get_company_IT_search, get_company_IT_full, or the docuengine tools. There is no explicit when/when-not or alternative routing. The word 'start' hints at a cheap entry point but it is not explained.

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