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

Annotations already declare readOnlyHint and openWorldHint, so safety is covered. The description adds real behavioral context beyond that: it fetches robots.txt, inspects specific on-page signals, and returns a 0-100 score with findings. It omits rate limits, caching, or failure modes for unreachable URLs.

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?

A single dense sentence with the purpose front-loaded, followed by the return shape. Every clause carries information — crawler list, eligibility check, readability signals, outputs — 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?

With no output schema, the description compensates by describing the return value (0-100 score plus findings list), and the single input is fully covered by schema and annotations. Only lack of guidance on siblings and edge cases keeps it from a 5.

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 with 100% schema coverage, so the schema fully documents the url field and the baseline is 3. The description's phrase 'public URL' slightly reinforces the input constraint but adds nothing the schema does not already say.

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 (check) and resource (AI crawler access to a URL), names all eight crawler user-agents checked, and enumerates the readability signals inspected. This is far more specific than the title, though it does not explicitly differentiate itself from siblings like ai_visibility_score or generate_ai_robots_txt.

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 implied by the description — you call it to learn whether AI crawlers can reach a page and how machine-readable it is — but there is no explicit when-to-use, when-not-to-use, or named alternative among the sibling tools.

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