subjack_check

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

With no annotations provided, the description carries the full burden of disclosing behavioral traits. It explains that a finding means the CNAME points to an unclaimed resource, notes that manual verification is required, and mentions the use of a subdomain wordlist and configurable threads/timeout. It does not explicitly state whether the scan is active or passive, but the overall behavior is sufficiently conveyed for the agent to understand the tool's operation and expectations.

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 well-structured with clear sections: a one-sentence summary, a brief explanation of the vulnerability, Args, Returns, and Notes. Every sentence serves a purpose, providing essential information without redundancy. It is appropriately sized for a tool with this complexity.

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?

Given the tool's complexity (4 parameters, no annotations, output schema present but not shown), the description covers the core aspects: purpose, parameter semantics, return value, and a key usage note. It does not mention any external prerequisites beyond the allowed_hosts entry, but that is a minor omission. Overall, the description is complete enough for an agent to invoke 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?

Schema description coverage is 0%, so the description fully compensates by documenting all four parameters in the Args section. It explains each parameter's purpose (domain, subdomains_file, threads, timeout), provides default values and constraints (e.g., threads max 100), and describes behavior when subdomains_file is not supplied. This adds significant meaning beyond the bare 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 states the tool's function: 'Check for subdomain takeover vulnerabilities using Subjack.' It specifies the resource (subdomain takeover) and the method (Subjack), which distinguishes it from sibling tools like subfinder_enum or dnsrecon_scan that focus on enumeration rather than vulnerability detection. The description also names the relevant services (GitHub Pages, S3, Heroku, Netlify, Azure), making the scope explicit.

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 provides clear context for use: it identifies that findings require manual verification and that the target must be in allowed_hosts, which are important operational prerequisites. However, it does not explicitly mention alternative tools or when not to use this tool, though the context implies it should be used when subdomain takeover is suspected. This is 'clear context, no exclusions' on alternatives.

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