send_email

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

With no annotations and only a one-line description, the tool's behavioral traits (e.g., authentication needs, rate limits, idempotency, error handling) are entirely opaque. The description adds no value beyond stating the basic action.

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 sentence, which is short but not concise—it omits essential information. Brevity without substance is under-specification, not conciseness.

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 complexity (6 parameters, nested object, no output schema), the description is severely incomplete. It lacks return value info, error conditions, prerequisites, or any operational context.

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 parameter schema coverage is only 33% (2 of 6 parameters have descriptions). The tool description adds no additional meaning to any parameter. For the undocumented parameters like 'html' and 'substitution_data', the description offers no help.

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 identifies the verb 'send' and the resource 'email'. It distinguishes this tool from siblings like 'create_template' or 'check_suppression'. However, it does not differentiate between 'test' and 'transactional' use cases, which could cause ambiguity.

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?

No guidance is provided on when to use this tool versus alternatives. Sibling tools like 'create_template' or 'get_deliverability_metrics' exist, but the description gives no context for choosing this tool over others.

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