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 of behavioral disclosure. It transparently lists the checks performed (syntax, disposable domain, MX plausibility), but it does not mention whether these checks are live/network-based, what the return format is, or any limitations or side effects. This adds meaningful context but is not fully transparent.

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, concise sentence that contains no fluff or redundant information. It is front-loaded with the primary verb and resource, making it easy to parse quickly.

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?

With no output schema and no annotations, the description leaves out crucial information about the return value or result format. The agent knows what aspects are checked but not what the tool returns (e.g., a boolean, a report, error behavior). For a verification tool, this is a significant gap.

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 provides a 100% description coverage for the single parameter 'address'. The tool description does not add any parameter-specific semantics beyond what the schema states, which aligns with the baseline score of 3 for high schema coverage.

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 the specific verb 'verify' and identifies the resource 'email address', while detailing three distinct aspects: syntax, disposable domain status, and MX plausibility. This is a clear and specific purpose statement, even without sibling tools to compare against.

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 guidance on when to use this tool versus alternatives, nor any exclusion criteria. The description only states what the tool does, leaving the agent to infer usage context from the name and description.

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