Audit a page's on-page SEO

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

No annotations are provided, so the description carries the burden. It discloses that it fetches a URL and returns data, but it does not mention potential side effects, error handling, redirects, or rate limits. The behavior is partially transparent but not deeply detailed.

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?

The description is a single sentence but long, listing many output items. It is front-loaded with the main action and then enumerates details. While not overly verbose, it could be more structured (e.g., bullet points), so it earns a 4.

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 must explain what the tool returns, and it does so by listing the specific SEO data fields. It lacks details on the response format or edge cases, but for a straightforward fetch-and-audit tool, it is reasonably 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?

The schema covers the single 'url' parameter with type and format. The description mentions 'Fetch a URL' which effectively clarifies the parameter's purpose, but it adds no additional semantics beyond the schema. With only one parameter and 0% schema description coverage, it is minimally sufficient.

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 clearly states the tool fetches a URL and returns structured on-page SEO data, listing the specific elements. This distinguishes it from sibling tools like extract_links or check_robots, which focus on different aspects.

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?

The description implies the tool is for on-page SEO auditing through its title and detailed list of SEO elements. It provides clear context but does not explicitly state when to use it over alternatives or mention exclusions, so it falls short of a 5.

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