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

Annotations declare readOnlyHint and openWorldHint, so safety is established. The description adds useful context: input format restriction and a per-call point cost ('[호출당 100포인트]'), which is a form of rate-limit disclosure. No contradictions with annotations.

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 composed of two brief, purposeful sentences (English and Korean) plus a format/cost note. It front-loads the main action, contains no filler, and every clause adds information.

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 simple one-parameter read-only lookup tool, the description, annotations, and schema together provide sufficient context including the operation, parameters, and cost. It does not specify the output format, but given the tool's simplicity and available annotations, this is not a critical gap.

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 100% with the 'ip' parameter already described with an example. The description adds value beyond the schema by explicitly stating that only IP address format is accepted ('IP 주소 형식만 허용됩니다'), which is a constraint not present in 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?

'Reverse IP lookup: list domains that have been hosted on a given IP address' uses a specific verb ('list') and resource ('domains hosted on a given IP'). This clearly distinguishes it from sibling tools like nslookup or whois, and the Korean title confirms the purpose.

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 implies usage via the action and format constraint ('IP 주소 형식만 허용됩니다') but does not explicitly state when to prefer this over alternatives like ip_history or nslookup, nor what would make a different tool more appropriate. Context is clear but no exclusions or alternatives are mentioned.

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