send_email

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

With no annotations, the description must carry the behavioral transparency burden, but it only says 'Send email via SMTP'. It does not disclose that sending is an irreversible external action, potential failure modes (e.g., authentication or network errors), rate limits, or whether the email is queued or sent immediately. This is minimal for a mutation tool.

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 concise at only four words, with zero filler or redundancy. It is front-loaded and easy to scan, effectively communicating the core action without unnecessary detail.

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 tool with 6 parameters and no annotations or output schema, this description is incomplete. It lacks operational details such as which body field to use (html vs text), how errors are surfaced, or whether prior authentication is required. The schema covers parameter names but not the tool's overall behavior or return semantics.

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 schema descriptions cover all 6 parameters with 100% coverage, so the baseline is 3. The tool description adds no parameter details beyond what is in the schema. The schema already documents recipient, subject, cc, bcc, html, and text, so the description provides no additional semantic value.

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 action as sending an email and specifies the transport method 'via SMTP'. This distinguishes it from sibling tools like save_draft or read_email, which handle different aspects of email management.

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. It does not mention that save_draft should be used for composing without sending, nor does it note any prerequisites like SMTP configuration or account authentication. The description merely states the action without contextual placement.

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