sendMail

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

With no annotations provided, the description carries the full burden of behavioral disclosure, but it only states the basic action. It does not mention side effects, permissions, rate limits, failure behavior, or return format. This is a significant gap for a mutation/side-effect tool.

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 first sentence is dense and front-loaded with useful feature information. The second sentence, 'Provides comprehensive email sending functionality', is largely redundant and does not earn its place. The definition could be trimmed without losing meaning.

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 (8 parameters, no annotations, no output schema, 0% schema coverage), the description is too thin. It lacks behavioral details, parameter specifics, and usage guidance that an agent would need to invoke the tool correctly. It provides only a high-level overview.

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 for 8 parameters. It does list several features (CC, BCC, text/HTML, attachments) that map to parameters, but it omits explicit explanations for 'useHtml', 'contentType', and the required 'subject' field. It adds some meaning beyond the bare schema but does not fully cover all parameters.

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 states a specific verb and resource: 'Send emails to one or more recipients'. It also enumerates supported features (CC, BCC, text/HTML, attachments), making the tool's scope clear. However, it does not explicitly differentiate itself from sibling tools like sendBulkMail, sendHtmlMail, or sendSimpleMail, so sibling differentiation is missing.

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 such as sendBulkMail or sendSimpleMail. It only implies usage by stating what it does. There are no exclusions, prerequisites, or contextual cues for selection.

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