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

With no annotations supplied, the description carries the full disclosure burden, and it does deliver a genuinely non-obvious behavioral trait: each file is validated by its body against an impossible address so soft-404 sites are reported as a false pass rather than a pass. That is exactly the kind of anti-footgun detail an agent could not get from the schema. It still omits what the response actually looks like and whether requests are rate-limited or authenticated.

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, no filler, and the action is front-loaded before the enumerated checklist. The second sentence, while dense, earns its length by explaining the soft-404 false-pass guard, which is the single most important thing to understand about the tool's results.

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?

The tool is a multi-check diagnostic with no annotations and no output schema, so the description must convey both behavior and result shape. It handles behavior well but never says whether the result is a per-check pass/fail list, a score, or free text, leaving the agent unable to anticipate what it will receive. For a two-parameter read tool that is a moderate but real 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 description coverage is 100%, so the url and api_key parameters are already fully documented inside the schema, including the header-wins precedence rule. The description adds nothing about parameter format or behavior beyond that. Baseline 3 is appropriate when the schema does all the semantic work.

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?

The description gives a specific verb and resource ("Check a website the way an AI agent meets it") and then enumerates exactly what is inspected: robots.txt, sitemap, llms.txt, API catalog, OAuth discovery, MCP server card, A2A card, and home page access. That is far beyond a restatement of the name. It stops short of a 5 because it never contrasts itself with the sibling fetch_page, so an agent must infer on its own that this is the multi-artifact audit rather than a single-page retrieval.

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?

There is no explicit when-to-use or when-not-to-use statement, no mention of cost, rate limits, or whether this should be run once per site versus per page. The purpose implies the usage context well enough that an agent can pick the tool for an agent-readiness audit, but nothing tells it when to prefer fetch_page or when to fetch a key via request_key first.

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