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

Without annotations, the description carries the burden of behavioral disclosure. It mentions a key behavior: 'The signing secrets are never shown again.' This is valuable because it informs the agent that secrets are not returned. However, it doesn't mention if the list is paginated, sorted, or limited, nor what happens if no destinations exist. It adds some transparency but lacks completeness.

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 extremely concise: two sentences, with no redundant words. The key behavioral note about secrets is included in the second sentence, which is important information. It is front-loaded with the primary content (URLs and verification status).

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 tool with no parameters and no output schema, the description is nearly complete. It tells the agent what is returned (URLs and verification status) and an important limitation (secrets not shown). However, it doesn't explain the output format (e.g., list vs. object) or any error handling (e.g., what if no destinations), but these are minor given the simplicity of the tool.

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 0 parameters and schema coverage at 100%, the schema is trivial. The description adds meaning by specifying the output content: 'URLs you have claimed and whether each is verified.' This goes beyond the empty schema, providing context that an agent needs about what the tool will return.

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 purpose: listing claimed URLs and their verification status. It is distinct from siblings like register_destination or verify_destination, though it doesn't explicitly name them. The resource ('destinations') and the action ('list') are clear.

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 this tool is for viewing destinations and their verification status, which is a read-only operation. It doesn't explicitly say when not to use it, but the context of siblings (register, verify, delete) makes it clear this is for listing. No explicit alternatives are given, but the purpose is evident.

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