Send email

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

No annotations are provided, so the description must carry behavioral disclosure. It does disclose a meaningful side effect—'A copy is saved to the IMAP Sent folder'—and the fixed sender address. However, it omits auth requirements, delivery/failure behavior, and whether sending is irreversible or async.

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 filler. The action and sender are front-loaded, and the remaining details about address formats and Sent-folder behavior are directly relevant to correct invocation.

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 schema plus description cover the core fields needed to send an email. However, given no annotationsholics, no output schema, and seven parameters, the lack of any note about result/error behavior, prerequisites, or when to prefer reply_email leaves the complete picture incomplete.

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 57%, so the description reasonably should add parameter meaning. It usefully explains the recipient address format for 'to', 'cc', and 'bcc', but it does not clarify subject handling, the text/html relationship, or attachment semantics beyond the schema's existing descriptions.

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 action: 'Send an email via SMTP from user@example.com.' It also adds recipient address format and the Sent-folder behaviorholics. It does not explicitly distinguish itself from reply_email, which is a related sending-oriented sibling, so it stops short of full sibling differentiation.

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?

There is no guidance about when to use send_email versus reply_email or the email lookup tools. The description provides operational context but no explicit when-to-use, when-not-to-use, or alternative routing.

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