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

Annotations already declare readOnlyHint, idempotentHint, and destructive false, so the safety profile is covered. The description adds that the operation returns 'rendered preview content' rather than raw draft metadata, but it doesn't explain response format or error behavior. It does not contradict annotations.

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?

A single eight-word sentence with no filler. The main action and object are front-loaded rank. It sacrifices detail for brevity but remains an efficient statement.

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 read-only tool, annotations already handle safety, but the description omits parameter purposes and any return/rendering details. Without an output schema, more guidance on what the preview content consists of would improve 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 description coverage is 0%, and the description does not explain the meaning of `id` or `request_id`. While `id` is somewhat self-evident, `request_id` is ambiguous and the description provides no clarification for either parameter.

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 uses the specific verb 'Read' with the object 'rendered preview content,' identifying the exact resource as 'candidate email draft.' This clearly distinguishes it from siblings like yardstick_email_drafts_read and other preview tools by emphasizing rendered output and candidate-specific 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?

No explicit when-to-use or when-not-to-use guidance is given. The purpose implies it is for previewing a draft before sending, but no alternatives are named or conditions stated.

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