Compose preview (does NOT send)

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

Description discloses no side effects (doesn't send or save) but lacks details on return value format and any limitations. Without annotations, more behavioral context (e.g., how preview is returned) would improve transparency.

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?

Three sentences, front-loaded with purpose and key constraint (does not send), no wasted 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?

For a tool with 9 parameters and no output schema, the description is minimal. It doesn't specify how the preview is returned or guide parameter usage (e.g., html vs text). More detail would increase completeness.

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 44%, and description adds no further parameter explanation beyond what schema provides. For the described parameters, it adds no new meaning; for undocumented parameters, it offers no guidance.

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?

Title and description clearly state the tool builds an email for review and does not send. It uses a specific verb 'build' and resource 'email', and contrasts with sibling 'send_email'.

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?

Explicitly says 'Does not send or save anything' and 'Use this first, then send_email after the user approves', providing clear when-to-use and when-not-to-use guidance.

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