verify-email

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

With no annotations provided, the description carries the full burden. It discloses the specific checks performed (MX, SMTP, disposable, catch-all), which is useful behavioral detail. However, it does not mention whether the check sends an email, the return format, possible errors, or limitations (e.g., SMTP checks being unreliable), leaving some transparency gaps.

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, well-structured sentence that front-loads the primary action and then adds relevant detail. Every word contributes value, with no redundant or filler content.

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 single-parameter tool, the description provides a clear picture of what is checked, but it omits what the output looks like. Without an output schema, the agent may not know whether the result is a boolean, a score, or a detailed report. It also does not mention any side effects, but the simple nature of the tool makes this a moderate gap rather than a severe one.

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 schema already describes the email parameter thoroughly ('Email address to verify'), and the description does not add additional meaning to this parameter beyond its overall purpose. Schema coverage is 100%, so the baseline of 3 is appropriate; the parameter is adequately documented but not enriched beyond the 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?

The description begins with a strong verb ('Verify') and specifies the resource ('email address') and the exact purpose ('deliverability'). It enumerates specific checks (MX, SMTP, disposable, catch-all), making its function clear and distinguishing it from sibling tools like find-email or domain-search.

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 implies the tool should be used when you have an existing email address to check for deliverability, but it does not explicitly state when to use this tool instead of alternatives like find-email or domain-search. There are no exclusions or alternative suggestions, so guidance is partially implied rather than explicit.

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