Look up IP addresses

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

Annotations already declare readOnly, idempotent, non-destructive, closed-world behavior, but the description adds genuinely new contract details: per-address failure isolation ('Other addresses are still processed after an error') and the found=false semantics for misses. It does not cover pagination or result-size limits, which keeps it from a 5.

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 tight sentences, front-loaded with the primary action and scope, followed by result semantics and the sibling routing note. Every sentence carries information and none repeats the schema.

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-value structure need not be described, yet the description still gives the key outcome variants (match record+network, found=false, per-address error). Combined with annotations and full schema coverage, an agent has everything needed 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 description coverage is 100%, and all three parameters (ips, fields, database) are documented in the schema itself, including ordering/duplicate behavior and field-path syntax. The description adds no parameter-level detail beyond 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 (look up), resource (batch of IP addresses), and scope (local MMDB databases). It also distinguishes itself from the sibling lookup_ip by explicitly noting the single-address alternative, so an agent can route without opening either schema.

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?

Directly names the alternative tool ('Use lookup_ip for a single address') along with the condition that selects it (batch vs. single). The batch framing plus the explicit alternative leaves no ambiguity about when this tool is the right choice.

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