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

Annotations already mark read-only and open-world; the description adds key behavior: a Google Web Risk blocklist hit forces an unsafe verdict, no charge when the blocklist is unreachable, and x402 payment via list_prices. It does not cover auth/permissions or rate limits, but adds meaningful billing and verdict logic.

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?

Front-loads the core operation, then lists report outputs, usage scenario, and billing caveat; each sentence carries distinct information. There is no repetition or filler.

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?

No output schema exists, so the description usefully summarizes verdict/score/TLS/redirects/headers and billing behavior. It leaves sibling selection implicit, but otherwise supplies enough to call 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 coverage is 100% and the single url parameter is documented as an absolute HTTP/HTTPS URL, so the description needn't re-specify it. The description only implies link input and adds no format or validation detail beyond the 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?

Names a specific operation: website safety check plus Google Web Risk blocklist lookup, and enumerates the full report fields. The 'plus'/'full report' phrasing distinguishes it from the basic sibling, though it never names check_site_safety or check_sites_batch explicitly.

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?

Gives a concrete use case: screening links before payment, login, or download, and points to list_prices for paid access. It does not state when to choose check_site_safety or check_sites_batch instead, so exclusions/alternatives are absent.

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