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

With no annotations provided, the description covers key behaviors: default draft-only mode, conditional sending, scope requirements, and that it returns a draft with preview. It does not detail error handling or edge cases, but provides sufficient transparency for typical use.

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 two concise sentences that front-load the main purpose and key behaviors, with no wasted words. It efficiently communicates the core mechanics and usage pattern.

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 the tool has 13 parameters and no output schema, the description provides a solid overall context: what it does, how to use it in two steps, scope requirements, and the return type (draft with preview). It doesn't address parameter conflicts, but covers the essential completeness for effective use.

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 input schema already has 100% description coverage, so the baseline is 3. The tool description adds context by highlighting the 'brief' and 'confirm_send' parameters as key toggles, and explains the overall workflow (draft then send). This adds value beyond the schema.

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 it launches a complete email campaign from a natural language brief, generating subject, design, and assembling on a list. It distinguishes from sibling tools like send_transactional_email and list_campaigns by focusing on campaign generation from a brief.

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 explicitly says by default it only creates a draft, and to actually send, one must call again with confirm_send:true or scheduled_at. It also mentions required scopes (write for draft, send for sending) and provides clear guidance on when to use each mode.

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