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

The description adds operational context beyond the readOnlyHint and openWorldHint annotations: it warns that a free key is required, and it explains that lite results come from a local dataset while max provides full intelligence. It does not discuss rate limits or error behavior, but the auth requirement is a meaningful addition.

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?

Three short sentences cover capability, mode semantics, auth, and an example with zero filler. The most important information is front-loaded and every sentence earns its place.

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 two-parameter read-only tool with complete schema descriptions and helpful annotations, the description provides everything needed to invoke it correctly, including the API key prerequisite. The only notable omission is any hint at response shape or invalid-input behavior, but this is a minor gap given the tool's simplicity.

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 description goes further by explaining kind='lite' as country/ASN from a local dataset and kind='max' as full intelligence, plus showing a concrete ips example. This adds value beyond the plain property descriptions.

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 starts with a specific action ('Look up 1-100 IP addresses in one call') on a well-defined resource (IP addresses), and the batch scope distinguishes it from sibling tools like ip_lookup_lite and ip_lookup_max. The kind parameter is also clarified with concrete meanings, so the agent knows exactly 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 1-100 IP range plus 'in one call' provides clear context for when the batch tool is appropriate versus a single-IP lookup, and the kind field tells the agent which mode to select. It does not explicitly name excluded cases or alternatives, but the batch framing makes the intended usage obvious.

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