send_email

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

No annotations are provided, so the description carries the full burden. It states 'Send an email' implying the email is dispatched, and mentions 'optional alias support'. However, it does not disclose side effects (e.g., email sent immediately, cannot be undone), authentication needs, rate limits, or default behavior for the 'from' field. Significant behavioral aspects are missing.

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 with only 7 words, 'Send an email with optional alias support'. It is front-loaded and every word adds value, covering the core functionality and a key differentiator. No unnecessary text.

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 9 parameters, no output schema, and no annotations, the description is minimally adequate. It captures the essence of sending an email with alias support, but does not clarify that this is for immediate sending (not scheduled or template-based), nor does it mention return values or prerequisites. Some context is missing for an AI agent to fully understand the tool's role among siblings.

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%, and all parameter descriptions are already present in the schema. The tool description adds no extra meaning beyond what the schema provides. For example, the 'from' parameter is already described as 'Send-as alias email address (use list_aliases to see available aliases)' in the schema. The baseline is 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 'Send an email with optional alias support' clearly states the action (send email) and the resource (email). It distinguishes from siblings like draft_email (draft vs send) and send_template_email (templates) by mentioning alias support, which is a unique feature.

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 that this tool is for sending immediate emails, optionally with an alias. However, it does not explicitly state when to use this tool versus alternatives like draft_email, send_scheduled_email, or send_template_email. No when-not or usage constraints are provided.

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