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

Annotations already declare read-only, non-destructive, idempotent, and closed-world behavior. The description adds useful behavioral context by listing the possible domain statuses and explaining that an active domain is required for shortened links, though it does not discuss auth or rate limits.

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 two concise sentences with the purpose front-loaded and the operational context immediately following. Every sentence adds value without repetition or waste.

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 zero-parameter, read-only list tool with no output schema, the description provides enough context: it names the resource, enumerates status values, and explains the active-domain requirement for link shortening. Annotations cover the safety profile.

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 tool has zero parameters, so parameter semantics are inherently complete. The description adds no parameter information because there is none to add, which is appropriate.

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 a specific verb and resource: listing the user's short-link domains and their statuses. It distinguishes this from single-domain retrieval by using the plural 'domains,' though it does not explicitly name sibling tools like get_link_domain or verify_link_domain.

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 usage by noting that a message sent with shorten_links: true needs an active domain, helping an agent understand why to check the list. However, it does not explicitly say when to use this tool versus create_link_domain, verify_link_domain, or get_link_domain.

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