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

Annotations already mark this as read-only, non-destructive, and open-world. The description adds clarity beyond annotations by stating 'Informational only' and explicitly saying it 'does not read or change any formation or company.' This is consistent with the annotations, with no contradiction.

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?

Two tight sentences. The core action and example are front-loaded, and the safety/scope clarification is concise without redundancy. 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 single-parameter, read-only lookup with an output schema and safety annotations, the description is complete. It tells the agent what the tool checks, what the input looks like, and that there are no side effects on formation/company data. No critical information is 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 0%, so the description carries the burden for explaining the parameter. It identifies the parameter as a specific fully-qualified domain and provides the example 'acme.com', which adds meaning beyond the raw schema pattern. It does not elaborate on formatting nuances, but for a single simple parameter this is adequate.

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 verb ('Checks'), a precise resource ('whether a specific fully-qualified domain... is available to register'), and gives an example. It clearly differentiates this from sibling tools like formation_check_name or check_company_name_availability by focusing on domain registration availability rather than company names.

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: use this when you need to know if a domain is registerable, and it emphasizes this is informational only. However, it does not explicitly mention alternatives, such as proceeding to a checkout/registration tool once availability is confirmed.

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