verify_email

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It only states the method (SMTP verification) and the outcome (valid/active) but does not disclose potential side effects, such as whether it sends an actual email to the address, triggers spam filters, requires a fromEmail, or has rate limits. This lack of detail for a tool with no annotation support is a significant gap.

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 clearly communicates the core function. It is front-loaded with the action and resource, with no wasted words or redundant information.

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 has no output schema, so the description should ideally indicate what the tool returns (e.g., a boolean or detailed report). The description says 'verify if...' but does not disclose the return format or any edge-case behavior. For a simple tool, this is adequate but incomplete given the lack of annotations and output schema.

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 schema already documents both 'email' and 'fromEmail'. The description adds minimal extra meaning beyond mentioning SMTP verification, which indirectly explains the role of fromEmail. Since the schema handles parameter documentation, a baseline score of 3 is appropriate.

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's purpose: 'Verify if an email address is valid and active using SMTP verification.' It specifies the verb 'verify', the resource 'email address', and the method 'SMTP verification', which distinguishes it from siblings like guess_email or check_domain_catch_all.

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 when to use this tool (when you need to check email validity/activity) but provides no explicit guidance on when not to use it or how it compares to alternatives such as check_domain_catch_all or get_mx_for_domain. There is no mention of prerequisites or alternative tools.

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