Send Email

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

Annotations already indicate a destructive write operation (destructiveHint=true, readOnlyHint=false). The description adds useful behavioral context by stating 'Sending is immediate — no confirmation step,' which informs the agent that the action is irreversible and immediate. It also introduces the draft-saving mode, going beyond the annotation baseline.

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 two sentences, front-loaded with the main purpose, and contains no filler. Every word adds value, making it perfectly concise and well-structured.

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?

The description covers both primary modes (send and draft) and highlights the immediacy of sending. The schema and output schema handle parameter details and return values, so the description is adequately complete for a tool with complex parameters, though it doesn't mention the recipient-ambiguity risk (which is addressed in the schema).

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?

The schema description coverage is 75%, meaning most parameters are already documented. The description adds minimal parameter-specific meaning, only indirectly referencing the `draft` parameter via 'save it to Drafts.' Since coverage is not high enough to warrant a 3 baseline automatically and the description doesn't compensate, a 3 is appropriate.

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 primary action ('Send an email') and the alternative ('save it to Drafts'), with a specific verb and resource. This distinguishes it from sibling tools like reply_email and forward_email, which focus on different email operations.

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 provides clear context for sending a new email or saving a draft, but it does not explicitly mention when to use this tool versus replying or forwarding, nor does it mention any exclusions or alternatives. This is a clear but basic usage description without comparative guidance.

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