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

Annotations already indicate read-only and open-world behavior, but the description adds material context not present in annotations: the data source is Shodan passive scans, results may be old, the actual monlist check is not performed, and billing occurs only on successful calls. These details materially affect interpretation and invocation.

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 tool's actual behavior and limitation, followed by relevant pricing details. Each sentence earns its place: what is reported, what is not checked, and what the call costs.

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?

The tool has an output schema, full parameter schema coverage, and annotations, so the description does not need to explain return format or safety semantics. The description supplies the remaining decision-critical context: passive/stale data, monlist-specific limitation, and pricing.

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 coverage is 100%, and the single required parameter is already documented in the schema as an IPv4 address. The description adds little parameter-specific guidance beyond reinforcing that the input is an IPv4 address, so it meets the baseline for high schema coverage.

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 verb and scope: it reports whether Shodan passive scan data shows NTP on port 123 open for an IPv4 address. It also explicitly clarifies that the tool does not run the monlist amplification check, which distinguishes it from what its name might imply and from active NTP audit siblings.

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 clearly establishes when the result is applicable: it is passive, possibly stale, and cannot determine whether monlist is enabled. It does not explicitly name an alternative active-scan tool, so it falls short of full when-to-use/when-not-to-use routing.

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