Check the email setup of a domain

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety and network-access profile is covered. The description adds scope (which records are inspected) but no additional behavioral traits such as rate limits, auth requirements, or latency from the probe option.

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?

A single front-loaded sentence that packs the record coverage, provider classification, and return contents with zero filler. Nothing is wasted.

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?

With no output schema, the description usefully signals the return shape (score out of 100 and a list of findings) and the audit scope. It is nearly complete, only missing guidance on the probe/selectors trade-offs already handled by the 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?

Schema description coverage is 100%, with probe, domain, and selectors all documented in the schema itself. The description adds no parameter-level meaning beyond that, so the baseline of 3 applies.

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 ('Audits') and resource ('domain email configuration') and enumerates the exact record types checked (MX, SPF, DKIM, DMARC, MTA-STS, TLS-RPT, BIMI) plus the disposable/free-provider detection. This clearly separates it from the generic lookup_dns, though it never names a sibling outright.

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 explains what is audited but gives no when-to-use context, no prerequisites, and no indication of when to prefer this over lookup_dns or verify_emails. The agent must infer the routing on its own.

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