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

With no annotations, the description carries the full behavioral burden. 'Passive DNS' does convey that this is a non-active historical lookup, but nothing is said about response behavior, rate limits, input constraints, or operational caveats.

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 compact and front-loaded, with no significant filler beyond the slight repetition of 'Passive DNS.' It is efficient, though somewhat skeletal for a tool with an undocumented parameter.

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 single-parameter tool with no annotations and no schema parameter descriptions, this definition provides too little to invoke it confidently. The output schema may explain results, but the input semantics and usage context remain ambiguous.

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 0%, so the description must compensate for the undocumented q parameter. It hints that q is probably a domain or IP via 'passive DNS resolution history,' but it never states the expected format, whether it accepts domains, IPs, or both, or how the default empty value behaves.

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 identifies a specific capability: retrieving passive DNS resolution history from OTX. This is clear enough to distinguish it from generic dns/dnsquery siblings, though it relies on a noun phrase rather than an explicit verb like 'query' or 'return'.

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?

No guidance is provided on when to choose this tool over related siblings such as otxdomain, otxip, or dnsquery. The phrase 'passive DNS' implies a context, but the description gives no exclusions, prerequisites, or alternatives.

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