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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds genuinely new information by explicitly stating it does not download malware samples, which tells the agent the payload bytes are out of reach and only metadata/hashes come back.

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 short sentences, zero filler, and the primary capability is front-loaded before the safety caveat. Nothing is wasted.

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, and the description does say what comes back at a high level (metadata and cryptographic hashes), which is enough for an agent to understand the return shape. Minor gaps remain around result ordering and whether the list is paginated or capped by the single limit parameter.

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?

There is one optional parameter with 100% schema description coverage, so the schema fully documents 'limit' including its default and max. The description adds nothing about pagination or ordering, matching the baseline-3 expectation when the schema does the heavy lifting.

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 resource ('List metadata and cryptographic hashes for payloads') with a scope qualifier ('recently observed by URLhaus'). It does not differentiate itself from the sibling urlhaus_recent_urls or urlhaus_lookup_payload, so an agent must infer which one applies.

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?

No when-to-use guidance, no alternatives named, and no indication of when to prefer this over urlhaus_recent_urls or urlhaus_lookup_payload. The only implicit guidance is the word 'recent', which is thin for a family of five sibling tools.

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