Hae asuntojen neliöhinnat (postinumero)

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

Annotations already cover read-only, idempotent, and open-world behavior. The description adds useful context beyond that: the data source (Tilastokeskus), the specific returned information (prices and transaction counts), and the grouping by dwelling type. It does not describe error behavior or availability, but this is not critical given the annotation coverage.

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 sentences with no filler: the first states exactly what is fetched and how it is organized, and the second tells the agent what to supply. The main content is front-loaded and every clause 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 two-parameter read-only lookup with full schema coverage, the description is sufficiently complete: it states the input requirement, the optional year, the output fields, and the output grouping. The lack of a formal output schema is mitigated because the description already explains what data to expect.

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%, with both parameters already documented including the postal code pattern and the year minimum/default. The description only echoes 'Anna postinumero ja halutessasi vuosi' and adds no format or constraint details beyond the schema, so the baseline score 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?

The description uses a specific verb ('Hakee') with a clear resource: old share-apartment square-meter prices and transaction counts by postal code from Statistics Finland. It also states the output breakdown by dwelling type, which clearly separates it from sibling tools like hae_polttoaineen_hinnat or hae_porssisahko.

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 gives clear context for when to use the tool: when Finnish apartment square-meter prices per postal code area are needed from Statistics Finland. It does not explicitly name alternatives or exclusions, but the sibling tools are sufficiently unrelated that the usage context is unambiguous.

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