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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and closed-world scope, so the safety profile is covered. The description adds useful disclosure about what is returned (verdict, check timestamps, freshness label), but says nothing about failure cases — e.g. what happens for an unknown or never-scanned slug — or rate limits.

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 sentences, zero waste: the leading question frames the intent immediately and the second sentence enumerates the returned signals. Nothing is repeated from the schema or annotations.

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?

An output schema exists, so the return-value enumeration is not strictly necessary, and the safety profile is in annotations. What is missing is the relationship to sibling tools — specifically how this differs from get_tool, which an agent would reasonably consider for the same 'tell me about this tool' intent.

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?

Single parameter with 100% schema description coverage, including a pattern and a reference URL format, so the schema carries the semantics. The description never mentions the slug or its expected form, so it adds nothing beyond the structured field — 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 action (check a tool's site liveness/status) and names the concrete payload: scanner verdict, verification timestamp, pricing timestamp, freshness label. It does not differentiate itself from siblings like get_tool, which could also plausibly return tool metadata, so an agent must infer the boundary.

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: an agent can infer this is for checking whether a listing is alive and how fresh its data is. There is no explicit 'use this when...' guidance, no exclusions, and no pointer to get_tool or compare_tools as alternatives for related needs.

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