Look up a Finnish company by Y-tunnus (business ID) from the YTJ Avoindata registry. Returns structured company information including name, status, legal entity type, and registration dates.
| Name | Required | Description | Default |
|---|---|---|---|
| id | Yes | Finnish Y-tunnus, format 1234567-8 |
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden of behavioral disclosure. It compensates by explicitly stating that the tool 'Returns structured company information including name, status, legal entity type, and registration dates,' which informs the agent about the output shape. It does not mention side effects (e.g., read-only nature) or error handling, but for a lookup tool these are largely implied, and the return-field disclosure adds meaningful transparency.
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 description is two concise sentences, front-loaded with the primary action and resource, followed by a clear summary of return values. Every word contributes to understanding, with no fluff or redundancy.
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 single-parameter lookup tool with no output schema, the description does well by explaining the return fields (name, status, legal entity type, registration dates). It does not cover edge cases, permissions, or error behavior, but such details are less critical for a simple read-only lookup. The description is sufficiently complete for an agent to invoke the tool correctly.
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?
The input schema provides 100% coverage for the only parameter 'id,' with a description: 'Finnish Y-tunnus, format 1234567-8.' The tool description adds no further parameter detail beyond mentioning 'by Y-tunnus,' which is already captured in the schema. Per the calibration rules, high schema coverage warrants a baseline score of 3.
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 clearly states the tool's purpose: 'Look up a Finnish company by Y-tunnus (business ID) from the YTJ Avoindata registry.' It uses a specific verb ('look up') and resource ('Finnish company by Y-tunnus'), making the action unambiguous. There are no sibling tools, so differentiation is not applicable, but the description is entirely self-contained.
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 description provides clear context for when to use the tool: when you need to look up a Finnish company by its Y-tunnus. It does not explicitly mention alternatives or when not to use it, but the scope is well-defined and there are no sibling tools that might compete for the same task. This aligns with a 'clear context, no exclusions' rating.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
With only one tool, there is no possibility of confusion between tools. The purpose of ytj_company_lookup is clearly defined and unambiguous.
The single tool name follows a descriptive convention (registry prefix + object + action), and with only one tool, there is no inconsistency to evaluate.
Only one tool feels thin for a server, even if the purpose is narrow. The count is borderline per the calibration guidelines, as a single tool may be insufficient for broader expectations.
The tool covers the core operation of looking up a Finnish company by Y-tunnus, but lacks additional likely operations such as searching by name or listing companies, which are minor gaps for this domain.