send-email

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

Discloses that email is sent immediately and cannot be unsent, requiring explicit user confirmation. Explains transport implications (SMTP vs AppleScript, MIME wrapping). Despite no annotations, description fully covers behavioral context.

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, front-loaded with core usage conditionals, no wasted words. Every sentence provides essential guidance.

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?

Comprehensive for a sending tool: covers target, safety, alternatives, transport details, return value (confirmation). Remaining schema descriptions plus output schema (exists) provide full picture.

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?

Adds meaning beyond schema: clarifies arrays for recipients, optional attachments, transport enum descriptions. Schema covers 63% of parameters with descriptions; description fills gaps and adds usage context.

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?

Clearly states it sends a single email now with recipients, attachments, and transport. Distinguished from siblings like create-draft, reply-to-message, forward-message, send-serial-email.

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 provides 'Use when' and 'Do not use when' conditions, listing specific alternatives for review, reply/forward, per-recipient copies.

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