create_campaign_draft

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

With no annotations provided, the description carries the full burden of disclosing behavior. It does this well by explaining that unset scheduled_at keeps the campaign a draft and that setting it causes the server to send when due. It does not cover side effects like whether the campaign becomes immediately visible or what auth is required, but the core safety-relevant behavior is clear.

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 tight sentences with no wasted words. The most important behavior ('WITHOUT sending it') is front-loaded, the draft/scheduled mechanism is second, and the sibling comparison is last. Every sentence earns its place.

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 7-parameter tool with full schema coverage, the description covers selection, the draft/schedule behavior, and the sibling alternative. The only real omission is the return value, since there is no output schema; stating that the call returns a campaign ID or status would make it fully complete, but this is not critical for selecting and invoking the tool.

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 100%, so the baseline is 3. The description adds real semantic value beyond the schema by explaining that scheduled_at is the draft/send switch: leave it unset for a draft, set it to send when due. This clarifies the most important parameter's behavior more concretely than the schema's 'RFC 3339 send time' note.

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 a specific verb and resource: 'Write a campaign' and immediately clarifies the key distinction 'WITHOUT sending it.' It also contrasts with send_campaign_now, so an agent can tell this tool apart from its closest sibling without opening the schema.

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 states when to use this tool: 'when a campaign should be reviewed first' and explicitly names the alternative condition: 'use send_campaign_now only when it should go out immediately.' This is direct when/when-not guidance with a named sibling.

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