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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the description does not need to restate that. It adds context about what 'active' means (promotions with discounts, free gifts, end dates) but does not disclose any pagination, empty-result behavior, or rate limits. Given the annotations cover the main safety profile, a 3 is appropriate – the description adds some value but not rich behavioral detail.

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?

A single, front-loaded sentence that includes the core purpose and scope, with zero filler. Every word earns its place, and the most important info (one SKU) appears first.

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 simple read-only tool with two well-documented parameters and no output schema, the description is sufficient for an agent to invoke it correctly. It could explicitly mention that it returns only active promotions and possibly that it may be empty, but the current text covers the essentials. No significant gaps that would prevent 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 100%, so both parameters (sku and locale) are fully documented in the schema. The description adds no additional meaning beyond what the schema already provides – it just restates that it applies to a single SKU. Baseline 3 applies 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 clearly states the verb (get), the resource (product promotions), and the scope (one SKU), and distinguishes it from siblings like get_cart_promotions (cart-level) and list_offers (broader). It also specifies the content types (discounts, free gifts, end dates), leaving no ambiguity about what the tool returns.

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 description implies usage for a specific product SKU, and the sibling names make it clear this is distinct from cart-level promotions. However, it does not explicitly state when NOT to use it or mention alternatives, though the context is sufficient for an agent to infer correct usage.

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