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

Annotations already disclose readOnlyHint=false, openWorldHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is largely covered. The description adds useful billing behavior ('$0.03 USDC per call'), but does not explain authentication needs, rate limits, or what the returned registration data contains. The added cost context is valuable but leaves notable behavioral gaps.

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 a single front-loaded sentence with no wasted words, and the cost is placed after the core purpose. It is appropriately concise for a simple tool, though its brevity reflects missing information rather than optimal economy.

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 paid, open-world lookup with two undocumented parameters and no output schema, the description is not complete enough. It should explain query format, jurisdiction format, and expected return content. The annotations cover some safety aspects, but the description still leaves critical invocation details unspecified.

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 0%, so the description must carry the full burden for both parameters. It only hints at the query subject via 'company registration' and says nothing about the optional 'jurisdiction' parameter or the expected format for either field. This provides minimal meaning beyond the schema's bare parameter names.

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 names a specific verb ('lookup') and resource ('Legal/regulatory', 'company registration'), making the tool's domain clear. It also distinguishes this tool from all siblings, none of which perform legal or company-registration lookups. It stops short of 5 only because the exact output or scope is not further specified.

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 offers no when-to-use, when-not-to-use, or alternative-tool guidance. It states what the tool is and its cost, but nothing about the conditions under which an agent should select it over the many sibling tools.

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