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

Annotations already declare readOnlyHint=true and openWorldHint=true. The description adds useful behavioral context: it notes that 'if a domain is entered, it finds the IP and returns the location,' and it discloses the cost ('30 points per call'). This goes beyond the annotation info without contradicting it.

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 concise overall but contains redundancy: the English and Korean sentences repeat essentially the same information. The unique details (domain resolution behavior and cost) are valuable, but the duplicated sentence could be trimmed for tighter structure.

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 single-parameter, read-only tool with no output schema, the description adequately covers what the tool does, its input behavior, and cost. It does not detail the exact return format (e.g., country, coordinates), but this is not critical for basic usage and is somewhat covered by the phrase 'geographic info.'

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?

The schema covers the single 'address' parameter with a description ('Domain or IP to search'). The tool description enhances this by explaining that for domains, the IP is first resolved before returning the location, adding meaningful input semantics that the schema alone does not provide.

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 the tool's function: 'Look up the geographic location of a domain or IP address.' It uses a specific verb and resource, distinguishing it from sibling tools like nslookup, whois, and ip_history which focus on DNS, reverse IP, or history rather than geolocation.

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 use for geographic lookup but does not explicitly state when to use this tool versus alternatives like reverse_ip or nslookup. It provides some context (domain resolution) but lacks exclusions or explicit comparison to sibling tools.

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