create_promotion

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

Beyond annotations, it discloses non-idempotency with the duplicate-effect consequence, server-side auth injection, throttling to the 30-per-10s cap, retry on 429/5xx, and the exact non-2xx error payload behavior. These are substantive behavioral details not present in the structured annotations.

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 organized into front-loaded, labeled sections (Behavior, Parameters, Returns, Use when) with no wasted sentences. It avoids repeating schema field details and packs each line with operational value.

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 having no output schema, the description covers response shape, status-return behavior, error mapping, auth, throttling, retries, and preconditions. For a mutating endpoint with one nested body parameter, this 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?

The nested body schema already documents every field (100% coverage), so the baseline is 3. The description adds important semantics: the whole payload goes in the single body argument, is forwarded verbatim, and while the schema marks body optional, this endpoint requires it.

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 opens with a specific action and resource: 'Create a new Promotion without coupons' plus the exact POST endpoint and response. The 'without coupons' qualifier differentiates it from the sibling create_coupon_promotion / create_coupons_promotion_bulk tools.

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?

It gives an explicit 'Use when' rule ('only when the user asked to create this') and advises verifying existence with a read tool first. Related Promotions tools are listed, but the description does not crisply state when to choose each alternative, so some routing inference remains.

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