Get eBay listing details

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the agent knows it's a safe read operation with external side effects. The description adds the specific data returned (price, condition, etc.) but doesn't discuss error behavior, latency, or rate limits. With annotations covering the safety profile, a 3 is appropriate.

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?

The description is two sentences: the first states the purpose with a clear list of fields, the second explains the parameter format. No fluff, front-loaded with the core function.

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?

Given a simple single-parameter tool with full schema coverage and safety annotations, the description is complete. It covers what data is returned, which is sufficient. No output schema exists, but the listed fields serve as a partial return description.

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?

The input schema description already explains the item_id formats fully (100% coverage). The tool description reinforces that it accepts either format but adds no new meaning beyond the schema. Baseline 3 is correct.

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 tool fetches full details for one eBay listing, enumerating specific data fields (price, condition, availability, seller rating, etc.). It distinguishes from siblings (search_ebay, find_deals) by focusing on a single item rather than searching or finding deals.

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 when you need full details for a specific listing, as opposed to search or deals tools. It does not explicitly say when NOT to use it or name alternatives, but the context is clear given the sibling names.

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