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

Annotations already cover readOnlyHint and openWorldHint, so the description adds real value beyond them by naming the three evidence sources (threat lists, Flockward findings, home-page scan) and the result vocabulary. A useful limitation is also disclosed — only the home page is scanned for hidden agent-directed instructions. Missing: latency/cost, caching, and what not_checked actually means.

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?

A single front-loaded sentence: verb and resource first, result categories second, evidence sources third. Dense but no filler; the trailing clause about the home-page scan is the only part that is slightly compressed.

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 one-parameter read-only lookup with no output schema, the description supplies the key missing pieces — the result categories and where the rating comes from. Remaining gap is operational (meaning of not_checked, cost of a scan), not structural.

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?

One parameter with 100% schema description coverage, so the schema already defines 'domain' with an example. The description adds nothing about format, normalization, or whether subdomains and full URLs are accepted — baseline 3 applies.

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?

States a specific verb and scope: 'Rate a whole website' and enumerates the four possible verdicts (safe, caution, unsafe, not_checked). The word 'whole' implicitly separates it from the URL-level siblings check_url/check_urls, but it never names them, so differentiation is inferential rather than 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?

Usage is only implied: 'whole website' suggests domain-level vetting rather than single-page checks, but there is no explicit 'use this when...' statement, no exclusion of the page-level siblings, and no guidance on preconditions such as domain ownership or whether unregistered domains return not_checked.

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