send-email

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

The description doesn't contradict the destructiveHint annotation (which indicates this is a write operation). It adds useful context about sending to multiple recipients, but doesn't disclose other behavioral traits like rate limits, authentication requirements, delivery confirmation, or what happens on failure. With annotations covering the destructive nature, the description adds some value but not comprehensive behavioral context.

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?

Two concise sentences with zero waste. The first sentence states the core purpose and API, the second adds a key capability. No redundant information, appropriately front-loaded with the essential action.

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 destructive tool with 8 parameters and no output schema, the description is minimally adequate. It covers the basic purpose and a key capability, but lacks information about error handling, response format, or integration context that would be helpful given the tool's complexity and destructive nature.

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 fully documents all 8 parameters. The description mentions 'multiple recipients at once' which aligns with the 'to' parameter's array capability, but adds no additional semantic meaning beyond what the schema already provides. Baseline 3 is appropriate when schema does the heavy lifting.

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 action ('send an email') and resource ('to your recipient email address'), and specifies the API used ('Mailtrap Email API'). It distinguishes from some siblings like template management tools, but doesn't explicitly differentiate from 'send-sandbox-email' which is a close alternative.

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 mentions 'You can send emails to multiple recipients at once' which provides some context about capability, but offers no guidance on when to use this tool versus alternatives like 'send-sandbox-email' or template-related tools. No explicit when/when-not instructions or prerequisites are provided.

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