Discounts: create campaign

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

Adds context beyond annotations: draft mode, no money charged, returns dispatches and offers. Discloses that confirmation is required before sending. Annotations (readOnlyHint=false, destructiveHint=false) are consistent; description clarifies non-destructive nature.

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?

Six sentences, no fluff. Front-loaded with purpose and immediate behavior. Efficiently conveys beta status, two-step workflow, return structure, and next steps.

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?

Despite no output schema, description explains return values (dispatches with id, status, recipient count; offers with price). Covers the tool's role in a two-step process and mentions prerequisite check, making it self-contained.

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 baseline is 3. The description adds extra context for itemIds ('listing IDs'), dryRun ('safe preview'), and idempotencyKey ('duplicate protection, conflict error'). Provides operational meaning beyond schema descriptions.

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 specific verbs ('creates a draft discount/special-offer messenger campaign') and resource ('list of listings'). It clearly distinguishes from the sibling tool msg_discounts_open_api_multi_confirm by labeling this as the first step.

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?

Explicitly states when to use (first step, not yet sent, no charge) and what not to expect (campaign is NOT sent). Mentions alternatives (confirmation tool) and prerequisite (check eligibility via another tool).

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