List Domains

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

No annotations are provided, so the description carries the full burden. It claims 'List all domains' but the input schema shows pagination (after, before, limit), indicating it returns a page, not all. The description does not disclose pagination behavior, rate limits, or authentication needs, making it misleading.

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 sentences, front-loaded with the core purpose and output, followed by a concise usage tip. Every word earns its place; no unnecessary text.

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 3 pagination parameters, no output schema, and schema coverage 100%, the description mentions output fields but fails to explain pagination or that 'all' is constrained by limit. It also does not clarify the result format. Adequate but incomplete for a list 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?

Schema description coverage is 100%, with full descriptions for after, limit, and before. The description adds no new parameter meaning beyond the schema, only a usage hint about IDs. Baseline 3 is appropriate as the description adds marginal value.

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 all domains from Resend and specifies the returned fields (domain names, statuses, regions, capabilities). This clearly differentiates it from sibling tools like create-domain, remove-domain, etc.

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 gives minimal usage guidance with 'Don't bother telling the user the IDs unless they ask for them,' but it does not explicitly state when to use this tool vs alternatives or provide exclusions. The context of sibling tools implies its use for listing, but explicit when/when-not guidance is lacking.

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