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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so safety is covered. The description adds valuable behavioral detail beyond annotations: domains are resolved to their first IPv4 address, and location is IP-level and approximate (not the site's physical address). This clarifies output semantics and limitations, earning a strong score given the existing annotation coverage.

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 two sentences and a related-tools line. It wastes no words: the first sentence states the core function and output fields, the second adds a critical caveat, and the final line lists related tools. All content is information-dense and front-loaded. There is zero fluff or redundancy.

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?

The tool has a single parameter and an output schema (indicated by 'Has output schema: true'), so return value documentation is handled structurally. The description covers the operation, input normalization (domain→IPv4), and approximation caveat, and points to related tools. For a simple read-only tool with rich annotations process, this is fully complete.

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 input schema already describes the single parameter 'query' with detail (types and auto-stripping of scheme/port/www). Schema coverage is 100%, so the baseline is 3. The description adds extra meaning: 'Domains are resolved to their first IPv4 address before lookup,' which clarifies behavior not in the schema. This additional semantics justifies a score above baseline.

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 opens with a specific verb-resource pairing: 'Resolve an IP address or domain name to its network operator and approximate location,' listing concrete attributes (region, city, coordinates). It explicitly distinguishes itself from related tools by naming dns, whois, and ns_reverse, and clarifies a key behavioral nuance (domain resolution to first IPv4 address). This is a clear, unambiguous purpose statement that leaves no doubt about what the tool does.

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 provides contextual guidance by stating the tool's focus (IP-level location) and explicitly listing related tools ('Related: dns, whois, ns_reverse'), which implies alternative choices. However, it does not explicitly state when to choose this tool over those alternatives (e.g., 'use whois for registrar info'). The intent is clear but not fully prescriptive, so it falls short of a 5 but exceeds a 3.

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