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

With no annotations, the description carries the full burden and does substantial work: it scopes the data source to the Czech vehicle registry, discloses the OSVČ matching asymmetry, and explains the two-part return value. It says nothing about partial-match semantics, result limits, or what happens on zero results, which leaves residual gaps.

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?

Two sentences, zero waste. The capability statement comes first and the edge-case caveat follows, so the essential information is front-loaded for an agent skimming definitions.

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?

Single-parameter tool with no annotations and no output schema, and the description covers the data source, searchable keys, the tricky OSVČ case, and the shape of the answer. Minor gaps remain around result-set behavior and match semantics, but nothing essential is missing for a correct 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 100%, so the baseline is 3; the description earns above that by adding semantics the schema cannot express — IČO matching on OSVČ must be exact, and the same field accepts either a name or a numeric identifier. It still doesn't clarify whether name matching is prefix, substring, or fuzzy.

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 (search), a specific resource (Czech companies in the vehicle registry), and the returned value (fleet size, vehicles held now / ever). The search-by-name-or-IČO framing makes it clearly distinct from get_company_fleet, which is a lookup for a known company.

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?

Explicitly states the key usage constraint: sole traders (OSVČ) are only findable by exact IČO, never by name, which prevents a whole class of failed calls. It does not name an alternative tool or say what to do when no result is found, so it stops short of full routing guidance.

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