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

No annotations are provided, so the description carries the full burden. 'Inspect' implies a read-only operation, but the description does not explicitly state that it is safe, non-mutating, or what happens on invalid domains. It lacks any disclosure about side effects, authentication, or rate limits.

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, front-loaded sentence that states the purpose directly without any wasted words. It is concise and structured effectively for quick comprehension.

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 simple one-parameter read tool with no output schema, the description adequately covers the primary purpose. It does not specify the response format or error behavior, but these are not essential given the simplicity and lack 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 description covers 100% of parameters, with 'domain' described as 'Public domain name.' The tool description adds no additional semantics beyond that, such as format examples or constraints, so it does not enhance what the schema already 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 uses a specific verb 'Inspect' and lists the exact resources (DNS records, mail configuration, SPF, DMARC) for a public domain. It clearly distinguishes itself from siblings like domain_health or email_validator_basic by its specific focus, even though it doesn't name them.

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 usage for anyone needing DNS/mail/SPF/DMARC data, but it does not explicitly state when to use this tool over alternatives or when not to use it. No exclusions or alternative references are provided, leaving selection largely to inference.

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