Send Email

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

Annotations provide no behavioral hints (no readOnlyHint, destructiveHint, etc.), so the description must carry the full burden. It effectively discloses the critical default dry_run=True behavior, which prevents accidental sending. This is valuable, but it does not mention other traits like authentication requirements, irreversibility of actual sends, or rate limits.

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 extremely concise: a single sentence that front-loads the purpose and immediately highlights the key dry_run behavior. Every word earns its place with no repetition or fluff.

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?

Despite the presence of an output schema, the description is very brief. It does not clarify what the tool returns (e.g., sent message ID or confirmation), nor does it address authentication needs, prerequisites (e.g., must have mail setup via mail_access_setup), or how it interacts with siblings. This leaves the agent with incomplete context for a tool with 7 parameters and many related siblings.

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%, meaning the description must compensate for the 7 parameters. However, it only mentions dry_run's default. The crucial parameters to, subject, body (all required) are not explained beyond their names. cc, reply_to_id, from_account are also undocumented. The description adds minimal meaning beyond the schema itself.

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 tool sends a Mail message, with the key behavior of default dry_run=True for preview. The verb 'Send' and resource 'Mail message' are specific. However, it does not explicitly differentiate from sibling tools like mail_create_draft, mail_open_message, or mail_search, which could cause confusion for an agent choosing among them.

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 mentions the dry_run default, which provides context on when to use this tool for preview versus actual sending. However, it offers no guidance on when not to use it, or alternatives among the many mail-related siblings. The context is clear but lacks exclusions or use-case boundaries.

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