ebay_get_combined_shipping_rules

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

readOnlyHint already declares the safe-read profile, so the bar is lower; the description still adds auth scope requirements (sell.account.readonly or sell.account) and the required X-EBAY-C-MARKETPLACE-ID header, plus marketplace-scoping. It does not mention failure modes or rate limits, keeping it at 4.

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?

Purpose is front-loaded in the first clause, with supporting detail about returned rules, ID workflow, and auth after. Slightly dense with some schema-duplicated header info, but no wasted sentences.

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?

With no output schema, the description usefully enumerates the returned rule types and states auth/header prerequisites, which is what an agent needs to call it correctly. Minor gap: no pagination or response-shape detail.

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 100% and the single enum parameter is fully documented in-schema. The description's note about the marketplaceId header largely restates the schema text, adding little new meaning, so baseline 3 applies.

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?

Specific verb + resource ('Get the seller's combined-shipping configuration for one marketplace') with an enumeration of the payload (calculated, flat, promotional rules, handling rule, payment window). It clearly distinguishes itself from sibling create/update shipping-rule tools by being the read-side entry point.

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?

Explicitly states the workflow relationship: 'Rule IDs returned here are needed by the update tools', routing the agent to ebay_update_calculated/flat/promotional_shipping_rule. No when-not guidance or exclusions, so it stops short of a 5.

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