send_email

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

With no annotations provided, the description carries the behavioral burden. It discloses the SMTP endpoint, port, implicit TLS, and the automatic save-to-Sent behavior. It does not mention potential side effects like external delivery or irreversibility, but the core send behavior and the Sent-folder copy are clearly stated.

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 two sentences, immediately front-loads the action and transport details, and includes the most important side effect in the second sentence. Every word earns its place with no fluff or repetition of schema fields.

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 send action with no output schema and no annotations, the description covers the critical operational facts: server, port, TLS, and Sent-folder persistence. It does not describe success/error returns, but the absence of an output schema and the simplicity of a fire-and-forget email send makes this a minor gap.

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 input schema has 100% description coverage for all six parameters, so the schema already documents meanings. The tool description adds no parameter-specific detail beyond the general 'send outbound email' context. This matches the baseline of 3 for full schema coverage.

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 states a specific action ('Send a new outbound email'), identifies the exact resource/transport ('one.com SMTP server (send.one.com:465 implicit TLS)'), and notes a behavioral side effect (saves to Sent folder). The word 'new' distinguishes it from sibling tools like reply_email, forward_email, and create_draft.

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 phrase 'new outbound email' gives clear context for when to use this tool, and the sibling list makes the contrast with reply/forward/draft tools apparent. However, it does not explicitly state 'use for new emails, not replies/forwards' or name alternatives, so it stops short of full exclusion guidance.

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