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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds genuinely useful context beyond that: the enumerated return fields, IPv4/IPv6 support, and crucially that each call consumes LeadBoxer credits — a cost signal annotations cannot convey.

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?

Front-loaded with the core mapping, then return fields, then usage, chaining and cost — every sentence carries information. The parenthetical 'reverse IP lookup, B2B website visitor identification' is slightly redundant marketing framing but takes little space.

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?

With no output schema, the description compensates by enumerating the returned fields (name, domain, ISP, connection type, location components). Cost, chaining, and input types are all covered, 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 single 'ip' parameter is fully documented (IPv4/IPv6 examples in the schema). The description's mention of IPv4/IPv6 largely restates the schema, so baseline 3 applies.

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?

States a specific verb+resource (IP → company identity) and immediately clarifies the reverse-lookup/B2B use case. The title and description together make it unmistakable versus lookup_domain and lookup_email.

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?

Gives concrete usage contexts (web logs, analytics, sign-ups, security alerts) and routing guidance ('Chain with lookup_domain for full firmographics'). It does not explicitly say when to skip this tool in favor of lookup_domain alone, so it falls short of a full when/when-not statement.

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