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

Annotations already declare readOnly, idempotent, non-destructive, and closed-world. The description adds useful behavior beyond them: it discloses that links are listed but not fetched (no network access) and that this is the same audit run pre-ship, giving the agent confidence about determinism.

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 checks are front-loaded in a single dense sentence that lists each audited element, and each clause earns its place. It is slightly run-on but not padded.

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 carries the return-value burden and does so by enumerating what is audited. It doesn't fully specify the result shape or how failures are reported, but it is sufficient for correct invocation.

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 coverage is 100%, so the baseline is 3, but the description adds real meaning by explaining why path matters ('so the canonical can be checked'). It doesn't explain response_type, but the enum and description in the schema cover that adequately.

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+resource (SEO audit of one page's HTML) and enumerates exactly what is checked: title, meta description, canonical, JSON-LD, h1, lang, og tags, internal links, and Flesch-Kincaid grade. This clearly separates it from siblings like readability, which only covers reading ease.

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?

It implies usage with 'Give the page's own path so the canonical can be checked' and clarifies 'Links are listed, not fetched,' but never states when to use this versus the readability sibling or when it isn't appropriate. The context is implied rather than explicit.

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