scan_url

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

With no annotations, the description carries full burden and does so thoroughly: requires API key, returns immediately with UUID (scan not finished), fetches URL from urlscan infrastructure (real interaction with hostile site), and explains visibility as a disclosure decision. All key behaviors are disclosed.

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?

Every sentence provides necessary operational or security context. The paragraph structure logically flows from high-level purpose to behavioral notes to parameter-specific guidance. No padding or repetition.

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 is complex with asynchronous behavior, security implications, and nuanced visibility choices. The description covers prerequisites, async pattern, safety warnings, and parameter semantics. Output schema exists, so return values need not be documented.

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 description must compensate. It explains tags (max 10), country (requests scanner location, e.g., 'fr'/'us'), and visibility (enum meanings and default). URL is self-evident. Slightly more detail on tag format could push to 5, but coverage is very good.

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 opens with 'Submit a URL to urlscan.io for scanning,' a specific verb+resource statement. It clearly distinguishes from siblings by referencing get_scan_result and explaining the async flow.

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 instructs to call get_scan_result after poll_after_seconds, explains when to use 'public' visibility, and warns not to submit URLs with session tokens or password-reset links. Provides strong when-to-use and when-not-to-use guidance.

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