tld.info

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

Without annotations, the description discloses the XOR relationship between parameters and lists outputs for domain mode but lacks details on error handling and exact return format for tld mode.

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?

Three sentences, front-loaded with purpose, no fluff. Every sentence provides essential information efficiently.

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 no output schema, the description adequately covers domain mode outputs but could be more precise about tld mode return structure.

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?

With 100% schema coverage, the description adds significant value by explaining the XOR logic and enumerating outputs for each parameter, surpassing the schema's minimal descriptions.

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 clearly states it provides 'TLD registry + Public Suffix List intelligence' and gives specific examples for both tld and domain parameters, distinguishing it from sibling tools like dns.lookup and domain.whois.

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 outlines two distinct use cases (TLD metadata lookup and full domain PSL analysis) and mentions applications like cookie scoping and rate limiting, providing clear context without explicit exclusions.

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