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

With no annotations provided, the description must carry the full behavioral burden. It discloses that the tool inspects live DNS records and evaluates DMARC policy levels (none/quarantine/reject), but it does not state that the operation is read-only, whether it makes external DNS queries, what permissions are needed, or what the response contains.

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 efficient sentence that front-loads the core action and the audited resources. It contains no filler, though it could be slightly more structured by separating what is checked from when to use it.

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 audit tool, the description covers what gets inspected but not what is returned. Because there is no output schema and no annotations, the definition should ideally say more about the result format or the fact that it performs read-only DNS lookups.

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%, so the single domains parameter is already well documented, including examples and the exact checks performed. The description does not add syntax, formatting, or validation details beyond what the schema provides, 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?

The description uses a specific verb and resource: 'Audit corporate domains' and then names the exact security checks (SPF, DMARC policy enforcement, MX infrastructure). It is clear what the tool does, but it does not distinguish itself from sibling tools such as audit_llmo_ai_readiness or verify_bulk_emails.

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 purpose implies when the tool is useful: auditing corporate domains for email spoofing and B2B cyber hygiene. However, there is no explicit when-to-use guidance, no exclusions, and no reference to sibling alternatives like verify_bulk_emails.

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