ebay_create_promotional_shipping_rule

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

Annotations only declare readOnlyHint=false, so the description carries real weight: it discloses that marketplaceId is transmitted as the X-EBAY-C-MARKETPLACE-ID header, that success returns eBay 204 No Content, the required auth scope (sell.account), and the verification path. This is useful behavioral context beyond the single annotation.

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 dense sentence, front-loaded with the core action, that packs the example, API mapping, header handling, return code, confirmation step, and scope requirement. Efficient, though it reads as a run-on carrying several distinct ideas.

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?

No output schema exists, and the description compensates by stating the 204-no-content return and how to verify (get_combined_shipping_rules). Auth scope is covered. A minor gap is that it doesn't fully contrast with the update tool or explain validation constraints.

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 and all nested fields are already documented in the schema. The description names the key sub-objects and the header mapping for marketplaceId, but adds little meaning beyond what the schema provides, so the baseline 3 holds.

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 (Create) and resource (promotional combined-shipping rule) and clarifies what the rule does with a concrete example (discounted/free shipping above an amount or item count). The parenthetical API mapping and the explicit field references (shippingRules.promotionalShippingRule, combinedDuration) make it unmistakable against siblings like ebay_update_promotional_shipping_rule.

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?

Gives the confirm-with-get_combined_shipping_rules follow-up and the sell.account requirement, which is clear context. It doesn't explicitly contrast create vs update_promotional_shipping_rule, but the create/update naming plus the confirmation step make intent clear.

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