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

With no annotations provided, the description carries the full transparency burden. It discloses meaningful operational details: prefix matching, case-insensitivity, absence of wildcards, and the shape of the return payload. It does not mention rate limits or error behavior, but for a public read-only search tool the disclosed semantics give an agent realistic expectations.

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 dense sentences with zero filler. The core behavior and return value are front-loaded, and the response-type hint ('for further lookups') is included without redundancy. Every phrase earns its place.

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 2-parameter search tool with no output schema, the description supplies the essential missing details: the matching rule and the high-level return fields. It could explicitly expand 'IČOs' for non-Czech agents or describe the result structure, but the description is sufficient for an agent to invoke it and interpret the response at a workflow level.

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 100% for both parameters, so the baseline is 3. The description's 'prefix match' phrase adds no new meaning because the schema already labels name as 'Company name or name prefix'. The limit parameter is fully documented in the schema, so the description need not repeat it.

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 ARES), and precise matching behavior (prefix match, case-insensitive, no wildcards). It also lists what the tool returns (IČOs, names, addresses), making its function distinct from likely siblings like check_vat or company_lookup without needing to open their schemas.

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?

Conveys clear usage context: use this when you have a company name and need identifiers/addresses to feed 'further lookups'. It stops short of explicitly naming sibling alternatives or exclusion conditions, but the search-focused wording and the ARES source give the agent enough behavioral context to select it appropriately.

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