hey_send_email

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

Annotations indicate mutating operation (readOnlyHint=false) and description adds immediate sending and return shape, but lacks details on potential side effects or failure modes beyond a brief mention.

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?

Two sentences with no unnecessary words; first sentence defines action and return, second provides direct usage comparison to siblings.

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?

Covers purpose, usage alternatives, and return format briefly. Lacks details on constraints like attachment support or rate limits, but sufficient for a simple send email tool given sibling differentiation.

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% with descriptions for all parameters; description adds no extra semantic meaning beyond the schema, meeting baseline expectations.

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?

Description clearly states 'Send a new email immediately' and differentiates from sibling tools hey_reply and hey_forward with specific usage contexts.

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 states when to use this tool vs alternatives: 'Use for standalone outbound messages; use hey_reply for thread responses, or hey_forward to share existing emails with new recipients.'

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