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

The description goes well beyond annotations by explicitly warning 'SENDS REAL TRAFFIC' and 'authorized targets only, confirm before calling.' It also discloses cost and async behavior, giving the agent critical side-effect information that annotations (readOnlyHint=false, openWorldHint=true) only hint at.

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?

Three tight sentences: purpose, safety warning, and async/cost. No filler, front-loaded with the core function and critical warnings. Every sentence carries necessary information.

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, safety, cost, and async behavior, but with no output schema it omits what the final scan results look like. It also leaves key parameters (scan_depth, authentication) unexplained. The provided warnings and async tip are valuable, but the tool remains under-specified for reliable invocation in varied scenarios.

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?

With schema description coverage at only 17%, the description must compensate, but it only explains async (via 'Pass async:true to get a job_id to poll instead of blocking'). It does not clarify target_url, scan_depth, exclude_paths, or authentication, leaving the agent to guess meanings of these required/nested parameters.

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 scans a web application for OWASP Top 10 issues and known CVEs using Nuclei. The verb 'scan' with specific resources ('web application', 'OWASP Top 10', 'known CVEs') distinguishes it from siblings like vuln_scan_network and sast_scan.

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 clear context: targets a web application, sends real traffic, requires authorization, and offers an async mode. However, it does not explicitly compare to alternatives (e.g., when to use sast_scan or vuln_scan_network), so it stops short of full exclusion guidance.

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