get_promotion_items

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

The readOnlyHint annotation already establishes that this is a safe read operation. The description adds useful context about the returned item structure, mentioning fixed_prices, level_info, and coupon_item_info, but does not describe pagination behavior or whether there are any rate or auth constraints.

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 sentences with no wasted words. The core action and scope are front-loaded, and the parenthetical return detail is compact and useful.

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 read-only tool with a simple schema and no output schema, the description is almost complete: it explains what is retrieved and names key return fields. Minor missing detail about pagination or response shape keeps it from being fully comprehensive.

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 100%, so the schema already documents id, page, and limit. The description adds no additional syntax, format, or constraints beyond indicating that id refers to a promotion. Baseline 3 is appropriate when the schema does the heavy lifting.

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: getting products, variations, or categories attached to a promotion. It also names the kind of data returned (discount details), which clearly distinguishes it from sibling promotion tools like get_promotion or list_promotions.

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?

Usage is implied by the description—use this when you need items attached to a promotion—but there is no explicit guidance about when to choose this tool over get_promotion, get_active_promotions, or search_promotions. No exclusions or prerequisites are mentioned.

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