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

With no annotations present, the description carries the full behavioral burden. It does disclose the upstream source (CBE/KBO Public Search) and the cost ($0.25 USDC), which are genuinely useful, but it omits not-found behavior, rate limits, and whether payment/auth must be pre-arranged before calling.

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 definition is compact and front-loaded: data source and keys first, output fields next, examples and price last. It reads as a dense fragment chain rather than prose, but no sentence is wasted and the examples earn their space.

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 9-parameter tool with zero annotation and zero schema-description coverage, the description does well on output shape and cost but leaves the majority of the input surface unexplained. An agent cannot confidently use 'limit' or the alias parameters based on this text alone.

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% across 9 parameters, and the description explains only two of them (enterprise_number and name). The alias-style parameters (q, be, bce, kbo, vat, number) and especially 'limit' are left entirely undefined, so an agent must guess whether they are synonyms, alternative inputs, or pagination controls.

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 names a specific verb and resource ('Belgian company lookup via CBE/KBO Public Search') and states the two lookup keys, which cleanly separates it from siblings such as fr_company, uk_company, and ch_company. It also enumerates the returned fields (legal name, status, legal form, seat, NACE, directors, capital, red flags), so an agent knows exactly what the call yields.

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 lookup keys and concrete examples ({enterprise_number:"0202239951"}, {name:"BNP Paribas Fortis"}), which is enough to pick the right input form. However, there is no guidance on when to prefer this over overlapping siblings like eu_vat, company_full, company_research, or kyb_report, nor any note on which key is authoritative when both are supplied or that there are no required parameters.

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