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

No annotations are provided, so the description carries the full burden. It does add genuine behavioral value by disclosing the underlying sources (PRH / YTJ) and the billing model ('1 point per returned record'), which matters for controlling max_items. However, it says nothing about authentication needs, rate limits, or pagination behavior beyond what the schema implies.

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 compact sentences with the resource and lookup key front-loaded and no filler. The cost note is appended rather than buried, though the return-field list is slightly tangential to the search action.

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 usefully enumerates the fields an agent will receive and flags the per-record cost, which compensates for the missing output schema. Pagination, defaults and status semantics are covered by the schema, so only auth/rate-limit context is absent.

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%, so the schema already documents keyword, status, max_items and start_page with examples and bounds. The description only echoes the return-field names (name, Business ID, status, municipality, link) and adds no syntax or format detail beyond the schema, so the baseline of 3 applies.

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) plus the exact resource (Finland company registry, PRH/YTJ) and the lookup key (company name), then enumerates the fields returned. It implicitly separates itself from the detail sibling run_fi_companies, but never names it, so sibling differentiation is left to inference.

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?

The phrase 'Search ... by company name' implies the appropriate context (keyword lookup against the Finnish registry) but gives no explicit when-to-use guidance, no prerequisites, and does not name run_fi_companies as the alternative for fetching a single known company. Minimum-viable context.

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