Audit email-domain security

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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=true, and destructiveHint=false, so safety and repeatability are covered without description help. The description adds the meaningful precondition that the domain must be authorized, plus the scope of records examined, but says nothing about rate limits, external lookups, or what an empty/misconfigured record set returns.

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?

One sentence, front-loaded with the verb and the record set, with zero filler. 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?

An output schema exists, so return values need not be explained, and annotations cover the safety profile. What is missing is routing context among the many DNS/security siblings and any expectation-setting about what the audit produces, leaving the definition adequate but not complete.

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%, so the description must carry the parameter burden. It implies the single input is a domain name and flags that it must be an authorized one, but gives no format guidance (bare apex vs subdomain, IDN/punycode, trailing dot). For a single self-evident parameter this is minimally adequate.

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 states a specific verb ('Inspect') and an enumerated resource set (MX, SPF, DMARC, MTA-STS, SMTP TLS reporting records), which cleanly separates it from network/DNS siblings like dns_enumeration or dnssec_posture_analysis. An agent knows exactly what class of check this performs without opening the schema.

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?

There is no explicit guidance on when to choose this tool over alternatives such as dns_enumeration or security_txt_analysis, and no when-not conditions. The only usage signal is the implicit 'authorized domain' precondition, which is a constraint rather than routing guidance.

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