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

Far exceeds the annotations: discloses one outbound HTTP request to the public domain, no storage, no authentication, a per-IP fair-use limit shared with grade_llms_txt, and a plain-text notice when the limit is hit. This is exactly the operational context an agent needs and cannot get from readOnlyHint/openWorldHint.

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?

Front-loads the action and return shape, then layers triggers, caveats, and limits efficiently. Slightly long, and the 'which is the point' aside is rhetorical padding, but every sentence carries information.

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 (a short plain-text summary, plus a plain-text limit notice). All an agent needs to call it correctly — input format, side effects, auth, rate limits, reliability caveat — is present.

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 'domain' parameter is already documented in the schema as a bare domain without protocol or path. The description only says 'the public domain you pass', adding no new syntax or format meaning, so the 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 verb and resource (fetches a public homepage) plus the exact output shape (two or three sentences on what the company does and who it serves). The scope constraints ('visible text only, no outside knowledge') make it unmistakable against siblings like grade_llms_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?

Explicit trigger — 'Use when a user asks how their site, or a competitor's, reads to an AI' — plus a caveat that the summary is model-generated and can be wrong on vague pages. It stops short of naming alternatives (e.g. when to prefer grade_llms_txt), so not quite a 5.

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