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

Annotations already declare readOnlyHint and openWorldHint, and the description adds useful behavioral context: the data can be stale, empty results use known=false, and billing is per successful call with failed calls not charged. The only slight ambiguity is the phrasing 'free, no key' alongside a paid x402 price, though the payment model is otherwise explained.

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 core purpose, then adds freshness, empty-result behavior, and payment details. Every sentence contributes operational information without unnecessary 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?

For a simple one-parameter read-only lookup with an output schema, the description provides enough context: what is returned, how stale the data may be, empty-result semantics, and pricing/billing behavior. An agent has what it needs to call the tool 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?

There is a single required parameter and schema description coverage is 100%, so the schema already explains the IP input. The description only restates that the tool targets an IPv4 address and does not add syntax or validation details 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 clearly identifies a specific resource and output set: Shodan InternetDB summary for an IPv4 address, covering open TCP ports, host names, CPEs, tags, and CVEs. It is easy to distinguish from generic search tools, though it does not explicitly differentiate itself from close security siblings like Censys exposure or open-port scanning tools.

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?

Usage is implied by the focus on an IPv4 host summary and the caveat that Shodan data may be days old, which helps decide when freshness matters. However, the description does not explicitly say when to choose this over sibling tools such as security_censys_exposure or security_open_port_scanner.

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