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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is covered. The description adds real value beyond that: it identifies the external public database queried and honestly discloses the false-negative limitation that a clean result only means 'not listed,' not safe.

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?

Two tight sentences with zero filler; the source and the scope are front-loaded and the caveat follows immediately. Every sentence earns its place.

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 single-parameter lookup with rich annotations and no output schema, the definition covers source, scope, and the key interpretation caveat. It does not describe the shape of the returned verdict or any rate-limit behavior, which would round it out.

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?

Only one parameter and schema description coverage is 100%, so the schema already documents it fully. The description adds no format, encoding, or example guidance for the URL input, so the 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 (checks) and resource (URL) and names the exact data source, URLhaus/abuse.ch, scoped to malware distribution URLs. That source detail implicitly separates it from ip_reputation and address_risk, though it never names a sibling 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?

The usage context is implied by naming the malware URL database, so an agent can infer 'use this to check if a URL is a known malware host.' But there is no explicit when-to-use framing and no routing guidance toward alternatives like typosquat_check, link_metadata, or redirect_trace.

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