preview_campaign_build

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

With no annotations provided, the description carries the behavioral burden and does add a key trait: 'Makes ZERO HTTP calls,' which is valuable and not inferable from the schema. Still, it does not disclose what the preview returns, whether required fields are validated, or how invalid input is handled.

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?

Two short sentences with no filler. The first sentence states the tool's full scope, and the second delivers the critical no-HTTP-calls behavior. Every sentence earns its place and is front-loaded.

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 nine parameters, no annotations, and no output schema, the description is too thin for an agent to invoke the tool reliably. It does not explain parameter semantics, required fields beyond their names, or what a successful preview produces, leaving substantial gaps for correct usage.

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%, so the description must compensate for missing parameter meaning. It mentions schedule, senders, tags, and lead-list mapping, but not the required name, subject, body fields or any semantics, constraints, or relationships between parameters.

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 'Preview' and names the exact resources: campaign, variants, schedule, senders, tags, and lead-list mapping. It distinguishes itself from sibling tools like create_campaign or launch_campaign by explicitly stating 'Makes ZERO HTTP calls,' which signals a non-executing preview behavior.

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 word 'Preview' and the guarantee 'Makes ZERO HTTP calls' imply this tool should be used for safe, side-effect-free validation before actually creating or launching a campaign. However, the description does not explicitly state when to use it versus alternatives, nor does it mention any when-not-to-use conditions or prerequisites.

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