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

Annotations already declare readOnly, idempotent, and openWorld, so the safety profile is covered. The description adds genuine behavioral context beyond them: domains are resolved to their first IPv4 before lookup, and results are IP-level/approximate and not the site owner's address. This is useful postcondition and limitation disclosure.

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?

Two tightly packed sentences plus a short related-tools line. The purpose and result set are front-loaded ahead of the caveat and related list, with no wasted text.

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 values need no explanation, and annotations carry the safety profile. The description still covers purpose, input forms, domain-handling behavior, and the approximate-location caveat, leaving nothing an agent needs to call it 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 100% and the query param is already documented (scheme/port/path/www stripping). The description adds meaning beyond the schema by clarifying that domains are accepted and resolved to their first IPv4 address, which the schema does not state.

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 ('Resolve') and precise resource ('an IP address or domain name'), then enumerates the returned fields (ASN, organization, country, region, city, coordinates, timezone). It names related siblings (dns, whois, ns_reverse), so an agent can distinguish this geolocation/ASN tool from adjacent lookups.

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 'Related: dns, whois, ns_reverse' line points at siblings but never states when to choose this tool over them or any exclusions. Usage is only implied by the returned fields and the domain-resolution note, with no explicit routing condition.

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