email_send

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

No annotations are provided, so the description carries full burden. It states 'send a one-off email' implying a write operation, but doesn't disclose behavioral traits like whether it requires authentication, rate limits, if emails are queued or sent immediately, error handling, or if it logs to analytics. This is a significant gap for a mutation tool with zero annotation coverage.

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 appropriately sized and front-loaded: the first sentence states the core purpose, followed by a structured Args/Returns section. Every sentence earns its place by providing essential information without redundancy, making it efficient and well-organized.

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's complexity (mutation with 4 params), no annotations, and an output schema exists (implied by 'Returns: Confirmation of email sent'), the description is partially complete. It covers parameters well but lacks behavioral context (e.g., auth, side effects) and doesn't fully compensate for missing annotations, though the output schema reduces need to explain return values.

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 0%, so the description must compensate. It adds meaning by explaining each parameter's purpose: 'to_email' as recipient address, 'subject' as email subject, 'body_html' as email body HTML, and 'contact_id' as optional link to contact. This clarifies semantics beyond the schema's basic titles, though it doesn't detail formats (e.g., HTML requirements) or constraints.

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 verb 'send' and resource 'one-off email to a contact', specifying it's not part of a sequence or batch. It distinguishes from siblings like email_preview (preview), analytics_sequences (sequence analytics), and sequence_activate (activate sequences), making the purpose specific and differentiated.

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 no guidance on when to use this tool versus alternatives. It doesn't mention when to choose email_send over sequence_activate for automated emails, or when to use email_preview for testing. There's no context on prerequisites, such as needing a verified sender or contact existence, leaving usage unclear.

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