ebay_get_listing

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

With no annotations, the description carries the full burden. It discloses the underlying API (Trading API GetItem), the types of fields returned (description, specifics, shipping, images), and the auth requirement (User OAuth token). This goes beyond a simple 'get listing' and provides useful behavioral context, though it could mention idempotency or rate limits.

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 three concise sentences with no extraneous words. The first sentence immediately conveys the core purpose, followed by relevant technical detail and auth requirements. Every sentence adds value.

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 one-parameter read tool with no output schema, the description covers the essential aspects: what the tool does, what it returns (including example fields), the API used, and auth. It does not cover error handling or pagination, but these are less critical for a single-item retrieval. Overall, it is sufficiently complete for an agent to use correctly.

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 schema description for 'itemId' is already provided (100% coverage), so the description adds little additional meaning. The phrase 'by item ID' in the description repeats the schema's purpose. Baseline 3 is appropriate since the schema already 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 'Get full details for a single listing by item ID', specifying the verb (Get), resource (listing), and scope (single). It distinguishes this from sibling tools like ebay_get_active_listings, which retrieves multiple listings, and ebay_get_listing_fees, which is fee-specific.

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 when to use this tool (for a single listing's full details) but does not explicitly name alternatives or provide exclusion criteria. Sibling tools like ebay_get_active_listings and ebay_get_listing_set exist, and no guidance is given on choosing between them.

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