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

Beyond the readOnlyHint/openWorldHint/destructiveHint annotations, the description adds crucial behavior: an empty list is a legitimate response meaning no sites exist, not a permission failure, and the tool works on all plans including Free. This directly helps an agent interpret results correctly.

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 front-loaded with the most important usage instruction and every sentence contributes meaningful guidance. The trailing 'Read-only' slightly duplicates the readOnlyHint annotation, but the overall structure is efficient and well organized.

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 effectively covers return values by naming the fields and clarifies important edge cases: no sites, any plan, and empty-list semantics. The information is sufficient for an agent to call and interpret the result correctly.

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?

With zero parameters and full schema coverage, the baseline is 4. The description reinforces that no website argument should be passed, which is useful given sibling tools do take such arguments, though it adds little beyond the empty schema.

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 lists every website in the account and specifies the returned fields: plan, last recorded score, and scan time. It distinguishes itself from add_website by explicitly saying it takes no website argument and by being the discovery-first tool.

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 gives explicit timing guidance: call this first when you don't know which domains the account holds or when the question names no site. It also clarifies that it works on every plan and that an empty result is a valid answer, and points to add_website for creating a site.

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