Port Scan

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

The description adds valuable behavioral context beyond the annotations by labeling the action as 'AGGRESSIVE — requires human approval' and stating that CDN ranges are excluded automatically. It does not elaborate on potential side effects or network impact, but the aggressive warning sufficiently covers the main concern.

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 well-organized, leading with a cautionary note, then the primary action, and followed by parameter-specific guidance. Every sentence contributes useful information without redundancy.

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 scanning tool, the description provides enough information to invoke it correctly: required target, optional ports with format, and the CDN exclusion behavior. The output schema is indicated as present, so the description does not need to explain return values, though a brief note on result format would make it fully complete.

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?

The schema provides no descriptions for either parameter, but the tool description significantly compensates by detailing the allowed values for 'ports' (including a default behavior). 'target' is not described, though its purpose is fairly obvious in the context of a port scanner, leaving only a minor gap.

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 states the action ('Discover open TCP ports') and the tool ('naabu'), making the primary purpose unambiguous. It also distinguishes itself from sibling scanning tools by explicitly focusing on TCP port discovery and excluding CDN ranges.

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 provides concrete usage context by explaining the 'ports' parameter options ('top-100', 'top-1000', or an explicit list) and the automatic CDN exclusion. However, it does not explicitly compare against alternatives like service_scan or when to prefer this tool over them, so it falls short of a 5.

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