send_email

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

The description discloses a notable behavioral trait: it manually constructs MIME to keep Unicode subjects readable, deviating from RFC-compliant encoding. However, it omits other important behaviors such as authentication needs, error handling, and whether it supports HTML bodies or attachments. Without annotations, the description carries full burden but is incomplete.

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 short (two sentences) and front-loaded with the core purpose. The second sentence is a technical note that, while relevant to behavior, could be more concise or separated into a behavioral section. No fluff, but the note adds complexity.

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 no output schema, no annotations, and minimal parameter info, the description is incomplete. It lacks details on success/error outcomes, prerequisites (e.g., authenticated Gmail), and the fact that 'to' is a single string. The behavioral note is valuable but does not compensate for missing context.

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 explain parameters. It only indirectly mentions 'subject' in the note about Unicode subjects, but does not describe 'to' or 'body' at all. 'Simple email' is vague and does not clarify parameter types or constraints.

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 'Send a simple email via Gmail', which specifies the verb (send), resource (simple email), and service (Gmail). It distinguishes itself from sibling tools by being the only email-sending tool.

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, nor does it mention limitations such as no attachments, single recipient only, or required authentication. The note about MIME construction is about internal behavior, not usage context.

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