check_domain_deliverability

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

No annotations are provided, so the description must carry the full behavioral burden. It discloses that a live DNS audit runs and that a score and warmup schedule are generated, but it does not state whether the operation is read-only, what permissions or rate limits apply, or whether any side effects occur.

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?

Well front-loaded and appropriately short for a tool definition. The enumerated checks are efficient and informative. The '(F6 Block)' label and the 'Args:' block are slightly extraneous but do not distract from the core purpose.

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. The description covers purpose, audit method, and both parameters sufficiently for invocation. It only misses explicit usage conditions or execution constraints (e.g., read-only nature, rate limits).

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 compensate. It does: `domain` is documented as accepting a domain name or email address with examples, and `selector` is marked optional with example DKIM selectors, adding clear meaning beyond the bare schema.

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 and resource ('Check domain email deliverability') and enumerates the concrete checks performed (SPF, DMARC, DKIM, MX, DNSBL) plus outputs (health score, warmup schedule). This clearly distinguishes it from the PR/journalist siblings, none of which relate to email deliverability.

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 to use it (validating a domain's email setup), but there is no explicit when-to-use, when-not-to-use, or alternative comparison. Since the sibling tools are unrelated, missing alternatives is low-risk, but guidance remains only implied.

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