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

The description adds critical behavior beyond annotations: create saves as a DRAFT and nothing is sent until workspace owner approval in the Email console, and it explains the A/B test structure. The annotations already state readOnlyHint=false and destructiveHint=false, and the description is consistent with them while providing valuable workflow context.

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 front-loaded with the core definition and then organizes the action-specific behavior compactly. It is appropriately sized for a multi-action tool and avoids wasted sentences, though it could be slightly tighter.

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 15 parameters, nested objects, and no output schema, the description covers the key action semantics, the draft approval workflow, status metrics, and A/B testing. It does not describe return formats for list/get/status beyond brief mentions, but is otherwise complete enough to call the tool 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?

Schema description coverage is 100%, so the schema already documents all 15 parameters thoroughly. The description adds some relational context around variants and abTest, but this mostly repeats or lightly elaborates on what the schema already provides.

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 defines the resource (email campaigns) and enumerates the four supported actions, making the tool's scope understandable. It does not explicitly name or differentiate from sibling tools like email_send or email_drafts, but the core purpose is 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 implies when each action applies and notes that create produces a DRAFT requiring owner approval, which is useful context. However, it provides no explicit guidance on when to use this tool versus alternatives such as email_send, email_drafts, or email_templates.

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