send_mail_v2

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

Annotations indicate destructiveHint=true and readOnlyHint=false, but the description itself adds no behavioral context beyond the endpoint. It does not explain side effects, idempotency, delivery behavior, or any external impact, so the agent must infer everything from annotations alone.

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 extremely short and contains no filler, but it is under-specified rather than genuinely concise. A single endpoint string does not earn its place because it provides almost no information beyond what the tool name already conveys.

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?

This is a complex tool with 11 parameters, required fields, no output schema, and no description. The response format, error behaviors, and mail-sending semantics are entirely unspecified, making the tool effectively unusable from the description alone.

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 only 9% (just dry_run has a description), and the tool description mentions no parameters at all. With 11 parameters including required email_from, email_to, and subject, the description fails completely to clarify what these fields mean or how they should be constructed.

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 is only the raw endpoint 'POST /api/v2/mail/send', which restates the tool's name and resource without explaining what the tool actually does in functional terms. It provides no plain-language purpose and does not differentiate from sibling tools like send_email or send_package.

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 such as send_email, send_package, or get_delivery_status. The description omits any context about prerequisites, preferred scenarios, or exclusions, leaving the agent without decision support.

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