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

Beyond the readOnly/openWorld/idempotent annotations, it discloses live lookup behavior, shared rate limits, partial failures, retryable refusals, concurrency of up to 3, and an approximately 22-second cutoff. These are meaningful operational constraints that an agent would otherwise not know.

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 front-loaded with the batch purpose and output shape, followed by usage guidance and then operational behavior. Each sentence contributes useful selection or invocation context without filler.

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?

Although an output schema exists, the description still summarizes the return content and covers rate-limit, timeout, concurrency, and partial-failure behavior. Given the tool's batch complexity and open-world annotations, it is complete enough for an agent 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%, so the single queries parameter is already fully documented, including the 10-target cap, supported target forms, and duplicate dropping. The description restates the target types and limit but adds little parameter-level meaning beyond the schema.

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 states a specific batch lookup action, enumerates supported target types, and explains the per-target result shape. It also explicitly differentiates from the single-target sibling by directing users to lookup_target for a full fact sheet.

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?

It gives concrete triage examples such as domains in a phishing report or IPs in a log excerpt, and it names lookup_target as the alternative for single-target full fact sheets. The usage boundary between batch and single lookup is clear.

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