Create promotion

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

Annotations already disclose write/non-idempotent/open-world behavior, so the bar is lower. The description adds genuinely useful context the annotations don't: plain dates are interpreted in the reporting timezone, and restriction arrays change the discount's scope. It stops short of covering duplicate-code handling or failure modes.

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?

Front-loaded with the core purpose, then four tight sentences covering the main configuration axes. Dense but every clause carries information; no filler.

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 17-parameter write tool with no output schema, the description covers the high-risk semantics (scope, dates/timezone, free-shipping, automatic vs code). Remaining gaps are advanced fields like extra_rules, which the schema documents adequately.

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 71%, and the description compensates on the ambiguous parts: it explains the applies_to default logic, the free-shipping recipe, and the timezone interpretation of starts_at/ends_at, none of which appear in the schema. Parameters like extra_rules and customer_group_ids are left to the schema, so it isn't exhaustive.

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?

States a specific verb and resource ('Creates a discount code (or an automatic promotion)') and immediately enumerates the discount forms it produces (percentage/fixed, order/products/shipping). This clearly distinguishes it from the sibling list_promotions, update_promotion and delete_promotion.

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?

Provides concrete configuration recipes ('Free shipping = applies_to "shipping", percentage 100') and states that restricting to products/categories/collections scopes the discount, which implies when to use each mode. However, it never names an alternative tool or an explicit when-not condition, so usage is only implied.

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