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

Substantially beyond annotations: it explains that availability is only reported when the registry clearly says free, that inconclusive lookups produce availability_checked=false and available=false meaning 'not confirmed' rather than 'taken', and that some TLDs have no registry service. It also discloses that brandability_score is subjective and that brandability_factors exposes the inputs.

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?

Front-loaded with the core action, then structured into two short caveat paragraphs. Slightly verbose in places but every sentence carries useful semantics; nothing is wasted.

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?

An output schema exists so return formatting need not be described, and annotations cover safety and open-world behavior. The one gap is the missing explanation of the required keyword_or_concept parameter, but otherwise the description is complete for calling the tool correctly.

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 50%; the tlds parameter is fully documented in the schema including its leading-dot regex constraint and defaults, but keyword_or_concept is undocumented anywhere. The description adds no parameter meaning, form, or constraints beyond what the schema already provides.

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-and-resource pair: suggest domain names and check them against public registry records. That is distinct from every sibling tool in the list, none of which deal with domain availability.

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 implies usage through caveats (confirm at a registrar, read inconclusive results as not-confirmed-free) but never states when to choose this tool over another or what prerequisites exist. Sibling tools are unrelated, so alternatives guidance is not strictly needed, but explicit when-to-use framing is missing.

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