domain_verify_smtp

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

With no annotations, the description carries the full burden of behavioral disclosure. It does specify that the tool checks DKIM, Return-Path, and DMARC records, which is a useful behavioral detail. However, it does not disclose the mechanism (e.g., DNS lookup vs. sending a test email), whether it is read-only, or what the output format looks like, leaving some ambiguity.

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 conveys the essential purpose without any redundancy. It is concise and easy to scan.

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?

The tool is simple with one parameter and no output schema or annotations. The description covers the core purpose but omits details about the result format or success criteria. For a verification tool, knowing the output structure (e.g., per-record pass/fail status) would improve completeness, but given the simplicity, the current description is minimally viable.

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 input schema description for the only parameter 'domain' is 100% covered, so the baseline is 3. The tool description does not add any extra meaning about the parameter format, validation, or examples, but it does contextualize what verification is performed on the domain.

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 tool verifies SMTP records (DKIM, Return-Path, DMARC) for outbound email. It uses a specific verb ('verify') and resource ('SMTP records'), and explicitly lists the record types, which distinguishes it from the sibling tool domain_verify_records that likely handles general DNS records.

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 clear context for when to use this tool: when you need to verify SMTP-related DNS records for outbound email. However, it does not explicitly mention alternatives or when not to use it, such as pointing to domain_verify_records for general DNS verification, but the scope is sufficiently clear.

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