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

Annotations already cover the safety profile (readOnlyHint, openWorldHint), and the description adds real behavioral detail: the exact crawlers checked, that it fetches the homepage impersonating four specific bots, and the runtime ('a few seconds'). It still doesn't say what happens on unreachable hosts or errors, so it falls short of a 5.

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, front-loaded with what is inspected and what is fetched, ending with the scoping caveat. Every clause earns its place with no 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?

For a single-parameter, read-only probe with no output schema, the description conveys the outcome it produces ('whether a bot wall blocks them') and the cost of calling it. The precise shape of the returned result is left unspecified, which is the only notable gap.

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 'domain' parameter is fully documented in the schema, including that only the host is used. The description adds no parsing or format guidance beyond that, so the baseline 3 is appropriate.

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 concrete verbs (reads robots.txt, fetches the homepage as named user agents) and the exact resource (AI crawler access for a domain). The closing 'does not count as an audit' implicitly separates it from the sibling audit_site, so an agent can tell the two apart.

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?

Explains the scenario clearly: a quick per-crawler access check that is explicitly not an audit, which tells the agent when to prefer this over audit_site. It stops short of naming the alternative tool or stating a hard when-not condition, so it is clear context without full routing guidance.

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