gmail_send_email

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

The description adds no behavioral context beyond what annotations already declare. With destructiveHint=true, the description does not mention irreversibility, side effects, or prerequisites. It simply restates the send action without operational details.

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 a single sentence with no filler, front-loaded with the verb 'Send'. While concise, it may be too terse for the tool's complexity, but it does not waste words.

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 5 parameters and a destructive action, the description leaves critical gaps: how to obtain the allowed recipient list, what happens on invalid recipients, and whether multiple recipients are allowed. The output schema exists but does not explain the allowed-recipient prerequisite or error behavior.

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 coverage is 0%, so the description must compensate. It adds a constraint on recipient_ids (non-empty, allowed subset) but provides no information about subject, body_text, body_html, or attachments. The coverage gap remains largely unaddressed.

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 identifies the action (send) and resource (email), and specifies a key constraint (non-empty allowed subset). It distinguishes from the sibling tool gmail_list_allowed_recipients by focusing on sending rather than listing. However, 'visible To' is slightly ambiguous, preventing a perfect score.

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 implies usage context through the 'allowed subset' constraint, suggesting the agent should first list allowed recipients via the sibling tool. No explicit exclusions or alternatives are provided, so the guidance is implied rather than stated.

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