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

No annotations exist, so the description carries the full burden; it does disclose the upstream data source (ares.gov.cz) and the price ($0.25 USDC), which are genuinely useful behavioral facts an agent cannot get elsewhere. It omits payment mechanics, error/not-found behavior, and whether exactly one of ico/name is required, which for a paid lookup call is a real gap.

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-loaded with the verb, source, and accepted keys, then the returned fields, then examples and price — a sensible information order with essentially no filler. The listing of return fields ('CZ-NACE, optional VR capital/court file, red flags') is dense but earns its place given there is no output schema.

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 no output schema and no annotations, the description does helpfully enumerate returned fields and disclose the price, which covers a lot of ground for a lookup tool. It is still incomplete for a 7-parameter paid endpoint: the undocumented alias-style parameters and the lack of any guidance on combining ico/name leave an agent guessing how to construct a valid call.

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 coverage is 0% across 7 parameters, and the description only explains ico (8 digits, with example) and name (with example). Five parameters — q, cz, dic, limit, and number — are left entirely undocumented, and 'dic' is especially confusing since DIČ is described only as an output field. The description adds real meaning for two params but does not compensate for the coverage gap.

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 and resource ('Czech company lookup via ARES') and names the authoritative source and both lookup keys. The country prefix plus the ARES reference distinguishes it cleanly from siblings like uk_company, pl_company, or company_full without opening any schema.

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 'by ico (8 digits) or name' and the two concrete examples, which tell an agent the two acceptable input modes. However, there is no explicit when-to-use versus alternatives such as company_full, company_research, or kyb_report, and no statement about what happens if neither or both keys are supplied.

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