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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint=false, so the safety profile is covered. The description adds a meaningful behavioral detail beyond the annotations: it costs $0.001 native USDC on Base, which affects invocation. It does not explain payment mechanics, auth needs, 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?

Two front-loaded sentences with zero waste: the first lists the inspection scope and the second states the cost. Every clause earns its place and nothing is buried.

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 tool with overlapping siblings and a paid invocation, the description omits essential routing guidance and parameter semantics. It never clarifies when to use this versus domain_email_security, domain_rdap, or email_preflight, nor does it explain the domain argument, leaving the agent under-informed for correct selection and invocation.

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 0% for the single required 'domain' parameter, so the description must compensate but does not mention the parameter at all. It gives no format, scope, or example for the domain input, adding no meaning beyond the schema's type and length constraints.

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?

States a specific verb ('Inspect') and enumerates the exact resources checked (DNS, CAA, SPF/DMARC/DKIM/BIMI, DNSSEC, RDAP, registrar-lock, nameserver redundancy). However, it does not distinguish this broad preflight from the overlapping sibling tools domain_email_security, domain_rdap, or email_preflight.

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 no when-to-use guidance, no conditions for choosing this over siblings, and no exclusions. It only states what is inspected and the cost, leaving the agent to infer that this is a comprehensive preflight rather than an email-specific or RDAP-specific tool.

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