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

Annotations already declare readOnlyHint=true, openWorldHint=true and destructiveHint=false, so the safety profile is covered. The description adds value by enumerating the returned redirect settings and giving the underlying REST endpoint, but says nothing about pagination behavior, ordering, or whether the primary domain is included. Adequate, not rich, given the annotations already carry the safety burden.

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 short, front-loaded sentences with zero filler: the resource and its payload come first, the endpoint trails as a compact identifier. Nothing could be removed without losing information.

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?

For a read-only list tool with full schema coverage and no output schema, the description compensates by naming the fields returned (enabled, type, destination), which the agent would otherwise have to discover at runtime. It omits edge cases such as empty results or whether redirects apply to the primary domain, leaving a small 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% – site_id, page and limit are each documented in the schema, including the 'pass the previous reply's next_page' chaining hint. The description adds no parameter-level detail, so the baseline of 3 is correct.

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 resource (the additional domains of a site) and discloses what each entry carries (redirect settings: enabled, type, destination). The word 'additional' usefully distinguishes the scope from a site's primary domain. It does not explicitly name or contrast with the close sibling spinupwp_list_site_path_redirects, so it falls short of a 5.

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 explains what will be returned but gives no when-to-use guidance, no exclusions, and does not point to spinupwp_list_site_path_redirects or spinupwp_get_site as alternatives. The agent must infer the use case purely from the name.

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