DNS records expected for a domain

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

The description adds behavioral details beyond the annotations by specifying the output format ('record by record') and content ('with the role of each'). This complements the readOnlyHint and idempotentHint, providing a clearer picture of what the tool returns without contradicting the stated constraints.

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 a single, focused sentence that avoids redundancy. It is front-loaded with the verb and resource, making the purpose immediately clear. No unnecessary words or enumerated lists that could obscure the message.

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?

The tool has a simple interface with one parameter and no explicit output schema, so the description suffices. It explains what is returned (DNS records, with roles) and implies the scope (declared domain). There are no missing elements like error handling or side effects, which are not required given the read-only nature and the absence of an output schema.

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 schema covers the 'domain' parameter (type string, required), and the description references it implicitly via 'declared domain'. However, no additional meaning is provided about the parameter's format, expected values, or examples. Given full schema coverage, a baseline of 3 is appropriate, and the description does not elevate it.

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 action (Return), the resource (DNS records), and the format (record by record, with the role of each). It effectively communicates the tool's purpose without ambiguity, distinguishing it from sibling tools that handle other email operations.

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 does not explicitly state when to use this tool versus alternatives. It implies the scenario of needing DNS information for a domain (likely for email setup), but this is not made explicit. There is no direct comparison to sibling tools, leaving the decision to the agent's inference.

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