send_email

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

The description accurately describes the side effect (sending an email) without contradictions. Annotations already indicate it's a write operation and not idempotent, so the description doesn't need to restate that. It adds no misleading information.

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 exceptionally concise: two short sentences that convey the essence of the tool. It includes the primary action, the immediacy, and the relationship to create_draft without any superfluous words.

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?

The description is complete for the tool's purpose. It clearly states what the tool does and its relationship to a sibling tool. Since an output schema exists, return values need not be explained. No critical information is missing.

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 description does not elaborate on any parameters, but the input schema provides full descriptions for all seven parameters with 100% coverage. Per the rubric, a high coverage warrants a baseline score of 3, and the description adds no additional meaning.

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 a new email immediately.' It also distinguishes itself from create_draft by explicitly noting it is a convenience wrapper with send_now=True, which removes ambiguity about its purpose compared to related tools.

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 implies when to use it vs. create_draft by presenting it as a convenience wrapper that sends immediately, but it doesn't explicitly contrast with other alternatives like reply or forward. It provides enough context for an agent to infer the appropriate use case.

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