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

Annotations already carry readOnlyHint=true, so the agent knows this is read-only. The description adds useful behavioral detail: results are per-query with individual statuses)Skip. The 'Disabled unless the operator enables batch queries' is a real constraint. Missing: output format, whether it fails wholesale on a single bad query, and any limits. With the readOnlyHint covering safety, the gap is the response shape. 3 is fair.

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 sentences, front-loads the batch behavior and the per-query result pattern, then adds the operational caveat about being disabled. No 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?

Adequate for a read-only batch lookup given the schema+annotation cover the parameter and safety. Lacks response format details, limits, and an explicit routing to the single-query sibling, which would complete it.

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?

One parameter with 100% schema coverage (the array of strings description is in the schema, but the description adds the accepted value classes: domain names, IPs, ASNs with an example). It's explicit enough that an agent knows what to pass. Slight deduction because there's no mention of batch size or format constraints, though the schema already covers array of strings.

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 precise verb (Query), the exact resource types (domain names, IP addresses/CIDR prefixes, ASNs), and the distinguishing scope (batch in one call, per-query results with individual statuses). An agent can immediately tell this from a single-lookup tool.

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 description tells the agent what the tool does and the operational constraint ('Disabled unless the operator enables batch queries'), but it never names the sibling whois_lookup or states when to prefer this batch tool vs. the single lookup. An agent can infer the intended use from 'multiple... in one call', but an explicit routing note would make it non-inferable. That's adequate but not thorough.

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