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

Annotations already establish readOnly/openWorld/non-destructive, and the description adds genuinely useful non-annotation context: instant execution, free of charge, no scoring, nothing stored, and that it works only from public pages. It stops short of describing failure modes or rate limits, so not quite 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 sentences, zero filler, and the highest-value information (what is checked, plus the free/instant constraints) is front-loaded before the sibling routing pointer.

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?

With no output schema, the description correctly pre-empts the return value by listing the five checks, and it covers cost and storage semantics. It could say more about how results are presented, but for a one-param read-only probe it is close to complete.

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 description coverage is 100% and the single 'website' parameter is documented there with a format example ('example.com'), so the schema does the heavy lifting. The description adds no syntax or format detail beyond the schema – baseline 3.

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 ('whether AI systems can read a website') and enumerates the exact five checks performed (robots.txt crawler access, llms.txt, Organization/FAQ structured data, title/description). It explicitly distinguishes itself from the sibling request_audit, so an agent can route without opening either schema.

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?

Gives explicit when-to-use ('checked instantly from its public pages', 'free, no score') and names the alternative with its selecting condition ('For the full audit — scored out of 100 and reviewed by a person — use request_audit'). Nothing is left to inference.

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