list_domains

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

With no annotations provided, the description carries the full burden. It discloses key behavioral traits: it's a read operation (implied by 'List'), returns structured data with status and tracking flags, and supports pagination via the example. However, it doesn't mention potential limitations like rate limits, authentication needs, or error conditions.

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 highly concise and well-structured: purpose, usage guidelines, return format, and example in four brief lines. Every sentence adds value without redundancy, making it easy to parse and front-loaded with essential 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?

Given the tool's low complexity (list operation with 2 optional parameters) and no output schema, the description is reasonably complete: it covers purpose, usage, return structure, and an example. However, without annotations, it could benefit from mentioning safety (read-only) or pagination defaults for full completeness.

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%, so the schema already documents both parameters ('page' and 'per_page'). The description adds minimal value with an example ('Example: { per_page: 50 }'), which hints at usage but doesn't explain semantics beyond what the schema provides. This meets the baseline for high schema coverage.

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's purpose: 'List sending domains.' This is a specific verb ('List') and resource ('sending domains'), making it immediately understandable. However, it doesn't explicitly differentiate from sibling tools like 'get_domain' or 'create_domain', which would be needed for a perfect score.

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 provides explicit usage scenarios: 'choose which domain to send from, or audit which domains are verified.' This gives clear context for when to use the tool. It doesn't specify when NOT to use it or name alternatives (e.g., 'get_domain' for a single domain), preventing a perfect score.

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