send_email

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It states the tool composes and sends, implying immediate action, but does not mention consequences like sent-item creation, error handling, rate limits, or whether the email is actually delivered immediately. This is minimal transparency 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 two sentences and front-loaded with the primary purpose. Every sentence earns its place; the prerequisite is concise and actionable.

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 no annotations and no output schema, the description covers a key prerequisite (get_identities) and the basic action. However, it omits expected return values, failure modes, or any clarification about whether this sends immediately vs. queued. Given the complexity of email sending and the rich sibling set, it is adequate but not fully complete.

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 already provides 100% description coverage for all parameters. The description adds only one piece of param-related context: connecting the identityId parameter to get_identities. This modest addition matches the schema-heavy baseline of 3.

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 'Compose and send a new email' clearly specifies the action and resource, distinguishing it from sibling tools like reply_email, forward_email, create_draft, and send_draft. The phrase 'new email' differentiates it from reply/forward workflows.

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 provides a useful prerequisite ('Use get_identities first') and implies this tool is for composing new emails rather than replying or forwarding. However, it does not explicitly compare with send_draft or other alternate sending tools, leaving some ambiguity that the agent must infer.

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