Email Send

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

Annotations already indicate readOnlyHint=false, destructiveHint=false, idempotentHint=false, openWorldHint=true. The description adds the important behavioral detail that a copy is stored in the Sent folder, which is beyond the annotations. It also implies side effects (sending) consistent with readOnlyHint=false. No contradiction. It could mention failure modes or rate limits, but the Sent folder detail is valuable.

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 that is concise and front-loaded with the primary action. It includes the key side effect without unnecessary detail. Every word earns its place.

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 has a rich schema (100% coverage) and an output schema, the description is mostly complete. It could mention that sending is irreversible or that attachments require local file access, but the schema already notes the local file access condition. The Sent folder side effect is disclosed. Overall adequate for an agent to invoke correctly.

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?

Schema description coverage is 100%, so the schema already documents all 9 parameters. The description adds no additional parameter-level meaning beyond what the schema provides. Baseline 3 is appropriate because the schema carries the burden.

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 an email'), the mechanism ('from the account (SMTP)'), and a key side effect ('store a copy in the Sent folder'). It is specific and distinguishable from siblings like email_save_draft, which would be the closest alternative.

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 usage for sending email but does not explicitly state when to use this tool versus email_save_draft or other email tools. It does not mention prerequisites like SMTP configuration or local file access for attachments, though the schema covers attachment_paths availability. No explicit exclusions or alternative routing.

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