page_facts

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

No annotations exist, so the description carries the full burden. It does valuable work by enumerating the report contents (redirect chain, robots sources including robots.txt for Googlebot, hreflang, problem detection), which is the main behavioral disclosure. It says nothing about failure behavior on unreachable URLs, JS rendering, rate limits, or response size, so the mutation/error surface stays opaque.

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-loaded with 'Free. Fetch one page...' before the long enumeration, so the reader gets the core action immediately. The trailing list is dense but every item is a distinct output field and earns its place; nothing is repeated.

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 and no annotations, the description has to describe returns, and it does so thoroughly by naming each reported field. Gaps remain around error paths, the meaning of 'problems found', and whether the fetch executes JavaScript, which matter for a fetching tool.

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?

The single parameter has 0% schema description coverage, so the description must compensate. 'Fetch one page' implicitly identifies the url argument as the target page, which is adequate for a bare string URL, but it adds no format, scheme, or normalization guidance beyond that inference.

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 pair (fetch, report) and a scoped resource (one page), then enumerates the exact SEO facts returned, so an agent knows precisely what the tool produces. It only hints at the sibling boundary via 'one page', without ever naming audit_pages, so it falls short of full sibling differentiation.

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 when-to-use, when-not-to-use, or alternative-naming language anywhere in the description. The sibling audit_pages covers overlapping SEO territory, and nothing here tells an agent which one to pick for a single URL versus a batch. The only marginally situational token is 'Free', which is a cost note, not usage guidance.

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