Send Email Batch

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

Annotations already indicate non-read-only and open world. Description adds context that it sends outbound emails, which is basic. Additional behavioral details like rate limits, partial failure handling, or idempotency behavior are not disclosed.

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?

Three sentences, each essential: purpose, attachment guidance, confirmation requirement. No wasted words, front-loaded with core functionality.

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 complexity and richness of the schema, the description covers key aspects: batch sending, attachment strategy, and user confirmation gate. Output schema exists, so return values need not be explained.

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 coverage is 100%, so descriptions in schema already explain parameters. The tool description adds value by advising on attachment usage (prefer attachment_id over inline base64), which aids agent decision-making.

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 it sends multiple outbound emails in one request, using specific verbs and resources. It distinguishes from sibling tool 'sending_send_email' (single email) by emphasizing the batch nature.

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?

Explicitly tells when to use (batch emails) and when not (requires user confirmation for every recipient and message). Also provides attachment best practices, differentiating inline base64 vs uploaded references.

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