masscan

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

With no annotations, the description carries the behavioral burden. It discloses key traits: asynchronous, ultra-fast, lacks service/version detection, and outputs a list of open ports with optional banner grab. However, it omits operational caveats like needing privileged/raw-socket access or the network-disruption potential of high scan rates, so it's not fully transparent.

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?

Five short sentences, each serving a purpose: definition, usage context, comparison, workflow, and output. Front-loaded with the core scanner identity and no filler. This is efficiently structured and easy to parse.

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 description covers purpose, when to use, key limitations, and expected output, fitting the 3-parameter schema well. Minor gaps – such as root privileges, runtime implications, or raw-packet side effects – keep it just short of fully complete for a network scanning tool.

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%, so baseline is 3. The description only indirectly references ports and rate via workflow and output, adding no new parameter-level meaning beyond the schema. It does not lift above the baseline.

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 specific verb and resource: an ultra-fast asynchronous TCP port scanner for large IP ranges. Explicitly contrasts with nmap for bulk scanning, making its identity distinct among siblings. The 'scan' + 'TCP ports' combination is unambiguous.

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?

Explicitly states when to use it ('scan large IP ranges') and provides a typical workflow: masscan to find open ports, then nmap for details. It also tells when masscan is insufficient – no service/version detection – giving clear guidance compared to siblings like nmap.

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