scan_url

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

Discloses async behavior (returns analysis_id immediately), recommended polling interval (every 5 seconds), possible verdicts, and pricing. Without annotations, the description carries full burden and does so fairly well.

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?

Relatively concise, but includes pricing information that, while relevant, may not be essential for tool selection. Front-loaded with primary purpose.

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 tool with one parameter, no output schema, and no annotations, the description is complete: covers async polling, verdicts, use cases, and pricing. No missing critical information.

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% (single url param with description and format). Description adds that URL must start with http:// or https://, which is already implied by the format. No additional semantic value beyond what schema provides.

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?

Clearly states the tool submits a URL for malware and phishing analysis across 70+ engines, distinguishing it from siblings like scan_file (file analysis) and check_scan_result (polling for results).

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?

Provides explicit use cases ('before navigating to an unfamiliar URL or when a user forwards a suspicious link') and directs to check_scan_result for polling, but lacks explicit when-not-to-use scenarios.

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