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

The description adds critical behavioral context by specifying that 'API keys are never returned.' This limitation on the data payload is a significant behavioral trait not captured by the provided annotations, making it highly useful for the agent.

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 definition is extremely concise and front-loaded. It achieves its goal in a single, direct sentence without any extraneous wording.

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 that there is no output schema defined, the description provides essential information about the return value being names only. This prevents the agent from erroneously expecting structured objects containing keys or other credentials.

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 all input parameters fully. The description adds no specific meaning or semantic context to the input fields (page, search, per_page) beyond what the schema provides.

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 resource (DNS providers) and the nature of the output (names only). While it identifies the purpose well, it does not explicitly name or differentiate itself from sibling listing tools.

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 offers no guidance on when to use this specific tool versus alternatives. It focuses entirely on the data returned rather than the use case or functional necessity of the tool.

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