send-mail

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

Annotations already mark this as destructive. Description adds details about MIME format saving to Sent Items and JSON allowing attachments. Does not contradict annotations. However, it omits other behavioral impacts like irreversibility or rate limits. Adds some context but not extensive.

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?

Relatively concise: four sentences plus a tip. Key information is front-loaded. The 'see here' placeholder is unnecessary but does not detract significantly. No redundant or tautological statements.

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 complexity of the input schema and presence of siblings, the description covers core functionality but leaves gaps: e.g., does JSON format also save to Sent Items? What about the SaveToSentItems parameter? The tip about list-users is helpful. Could be more complete.

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 high (75%), so baseline is 3. Description adds value by explaining that JSON format allows inline attachments and that recipients should not be guessed. But does not go into detail on many parameters (e.g., SaveToSentItems, which is in schema). Adequate but not exceptional.

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?

Clearly states 'Send the message specified in the request body' with verb and resource. Mentions JSON/MIME formats and attachment capability. However, it does not explicitly differentiate from siblings like forward, reply, or send-draft, relying on context. Still, purpose is well-defined.

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?

Provides some guidance: mentions creating a draft as an alternative and warns against guessing email addresses (use list-users). But does not specify when to use this vs. other send-related tools (e.g., forward, reply, send-draft). Lacks explicit when-not-to-use scenarios.

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