send_email

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

With no annotations to fall back on, the description provides essential behavioral context: it accepts only a confirm token, the payload cannot be altered, tokens are single-use and expire after 10 minutes, and dry-run mode (the default) simulates without sending. This is comprehensive and directly informs the agent of safety and constraints.

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 three sentences long, front-loaded with the core action, and every sentence contributes meaningful information. There is no redundancy or filler.

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?

For a simple one-parameter tool with no output schema, the description covers the prerequisite (preview_email), token constraints, and default dry-run behavior, making it complete enough for an agent to invoke correctly.

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?

The only parameter, confirm_token, is thoroughly explained in the description: it is the token from preview_email, single-use, and expires in 10 minutes. This adds significant meaning beyond the bare input schema, fully compensating for the 0% schema description coverage.

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 explicitly states the tool's function: sending an email previously rendered by preview_email. This clearly distinguishes it from the sibling preview_email tool and makes the purpose unambiguous.

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 clearly implies the tool should be used after preview_email by stating it sends the email 'previously rendered.' However, it does not explicitly mention when not to use it or provide alternative tools for sending, so it falls short of a full 5.

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