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

With no annotations, the description carries the full burden. It clearly discloses the key side effect: emails are SENT for real automatically after scheduling. It also states the approval prerequisite, which is essential safety context. It does not cover cancellation, failure modes, or what happens if slots are unavailable, but the critical behavioral facts are present.

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 compact sentences with zero wasted words. The operational effect is front-loaded, and the approval prerequisite follows immediately. The structure is appropriately sized for a one-parameter tool.

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 no annotations, one fully described parameter, and no output schema, the description includes the essential information: what it does, that emails are really sent, and that prior preview approval is required. It omits secondary details such as post-scheduling cancellation or failure behavior, so it is not fully exhaustive but is complete enough for correct invocation.

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% for the single id parameter, and the schema already documents that the id is a campaign UUID from list_campaigns. The description adds no additional parameter meaning beyond the schema, so baseline 3 is appropriate.

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 states a specific verb and resource: it spreads ready prepared emails over the campaign's working-hour slots, then sends them automatically. It distinguishes this from preparation and preview by emphasizing emails are SENT for real and that prior approval of preview_schedule_campaign_delivery is required. An agent can tell this apart from prepare_campaign_emails, preview_schedule_campaign_delivery, and send_campaign_emails_now.

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 provides a clear prerequisite: only use after the user approved preview_schedule_campaign_delivery. It does not explicitly mention alternatives such as send_campaign_emails_now or conditions when not to use this tool, so it falls short of full when/when-not/alternatives guidance.

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