request_email_otp

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

The annotation destructiveHint=true already signals a state-changing/side-effect operation, and the description adds the context of using a ThaiBulkMail OTP template. Beyond that, it does not disclose additional behaviors like rate limits, costs, or return formats, but given the annotation coverage, a score of 3 is appropriate.

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, front-loaded sentence with a clear verb and object. It follows the pattern of stating the action, target, and service, with zero wasted words.

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?

Given the tool's simplicity (2 required params, no output schema), the description sufficiently explains what it does and mentions the external service (ThaiBulkMail). The destructiveHint annotation covers side-effect expectations. While it does not elaborate on return values or failure cases, the tool is straightforward enough that this is acceptable.

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 baseline is 3. The description's mention of 'ThaiBulkMail OTP template' echoes the schema description for template_uuid without adding new meaning about parameter formats, constraints, or relationships. No extra semantic value is provided 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 uses a specific verb ('Send') and identifies the resource ('OTP code via email') and service ('ThaiBulkMail OTP template'). It clearly distinguishes this tool from siblings like send_sms (SMS OTP) and request_otp (generic OTP request) by specifying email delivery and template usage.

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 clearly implies the tool is for sending email OTPs via ThaiBulkMail, which is a distinct use case among the siblings. However, it does not explicitly state when not to use it (e.g., not for SMS) or mention alternative tools by name.

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