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

Annotations already establish that it is read-only and open-world. The description adds important behavioral context beyond annotations: public open data, no API key, paid access via x402, and that failed calls are not charged.

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 purpose and returned fields are front-loaded in the first sentence, while the second covers access/payment details. There is no wasted text, and every sentence 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 two-parameter lookup tool with an output schema, annotations, and full schema coverage, the description is complete enough. It covers the data source, return fields, access conditions, and payment behavior.

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%, and both parameters are documented in the schema itself. The description mentions name-based search but does not add parameter-specific guidance beyond what the schema already provides, 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?

It states a specific verb and resource: searching companies in the Norway Business Register via Brønnøysund. The country-specific framing clearly distinguishes it from sibling country registries such as Sweden, Finland, or Ireland.

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?

Usage is implied by 'searches companies by name' in the Norway register, and the public/no-key note helps context. However, it does not explicitly say when to choose this over sibling company-registry tools or note any exclusions.

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