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

Beyond the readOnlyHint/openWorldHint annotations, the description discloses the official open-data source, CC BY 4.0 license, daily update cadence, returned field set, and the paid x402 pricing model with failed calls not charged. This is exactly the kind of behavioral context an agent needs for a paid read-only data tool.

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 compact and front-loads the source and operations before listing returned fields and pricing. It is dense but every element is useful; the long field list is justified by the tool's data-lookup nature.

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?

Given the tool's complexity, a payment model, and an output schema already covering return values, the description provides enough source, licensing, update, lookup, and billing context to call it correctly. Nothing material appears to be missing.

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 input schema already documents all four parameters with examples such as 'ryanair' and '104547'. The description reinforces the name vs. company-number lookup paths but adds no additional syntax, defaults, or paging details beyond the schema.

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 states a specific resource (Irish companies from the CRO), the operation (search by name or look up by company number), and the data provenance. It clearly distinguishes itself from the many other country/company registry siblings through the Ireland/CRO scope.

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?

It tells the agent the two supported access patterns: search by company name or look up a company number, which maps naturally to the schema parameters. It does not explicitly say when not to use it or name alternative sibling tools, so it stops short of full routing guidance.

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