ebay_get_ads_by_inventory_reference

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

The annotations already declare readOnlyHint=true, so the read-only nature is covered. The description adds nothing beyond that – no mention of pagination, response format, rate limits, or any behavioral nuances. Since the annotation already covers safety, the description's failure to add context like the scope of results (single campaign, all matching ads) leaves a gap.

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 a single, short sentence – concise and front-loaded. However, it is so brief that it conveys almost no information beyond the tool name. It is not verbose, but it sacrifices substance for brevity, making it minimally acceptable.

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 3 required parameters and no output schema, the description should explain what the response looks like or what 'inventory reference' means, but it does not. It also fails to clarify the scope (e.g., returns ads for a specific campaign and inventory reference) or how it relates to bulk variants. The description is incomplete for an agent to confidently invoke it without additional context.

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% per the signal, so the baseline is 3. However, the schema descriptions are tautological (e.g., 'campaignId required endpoint parameter'), providing no real meaning beyond parameter names. The tool description itself does not elaborate on parameter relationships or expected values, so it adds no value beyond the schema's minimal text.

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 states the verb 'Get' and the resource 'ads by inventory reference', which clearly indicates what the tool does. However, it does not differentiate this from many sibling tools like ebay_get_ads, ebay_get_ad, or ebay_bulk_get_ads_by_inventory_reference. The mention of 'eBay Marketing API' adds minor context but no distinguishing detail.

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?

There is no guidance on when to use this tool versus alternatives. It does not mention that this is for a single inventory reference, versus bulk operations, or when to prefer it over ebay_get_ads. The description provides no context for selection among the large set of sibling tools.

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