gmail_send

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

No annotations are present, so the description must disclose side effects and requirements. It states supported features (HTML, CC/BCC, threading) but does not clarify the implications of sending (e.g., immediate delivery, need for authentication, irreversibility). The lack of detail about how threading works (via thread_id/in_reply_to) leaves important behavioral aspects undisclosed.

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 two sentences, front-loaded with the action, and contains no filler. Every sentence provides relevant information about features, making it very efficient.

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 has 8 parameters and no annotations, the description is too minimal to be fully actionable. It doesn't provide context on prerequisites, formatting of recipients, or how threading parameters are used. The output schema exists, so return value details are not needed, but parameter usage and edge cases are missing.

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?

With 0% schema description coverage, the description must compensate for parameter meaning. It maps to some parameters (HTML, cc/bcc, threading) but fails to explain the format of 'to', 'subject', 'body', or how 'thread_id' and 'in_reply_to' relate to the threading feature. This is insufficient for 8 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 starts with 'Send an email', clearly identifying the verb and resource. It distinguishes itself from sibling tools like gmail_draft and gmail_send_draft by specifically stating it sends an email, and the added features (HTML, CC/BCC, threading) further clarify its scope.

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 indicates the tool's purpose (sending email) but provides no explicit guidance on when to choose it over alternatives like gmail_draft or gmail_send_draft. The usage is implied by the verb, but there are no exclusions or alternative tool references, making it less helpful for selection among related gmail tools.

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