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

Annotations already declare readOnlyHint=true and openWorldHint=true, covering the safety profile. The description adds only that results are 'summaries' (not full detail) and batched; it says nothing about partial-miss behavior, ordering, or limits, which the schema already partly covers.

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 front-loaded sentence with the resource and the batch scope first; every word earns its place and there is no filler.

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 annotations covering safety, an output schema covering return values, and a fully documented single parameter, the description is nearly sufficient. A brief note on how many ids are practical or what a summary omits would close the remaining gap.

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% and the schema itself documents the up-to-9 limit and comma-separated/repeated syntax. The description's 'multiple ids' adds no meaning beyond the schema, so the 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?

States a specific verb+resource ('eBay Live stream summaries') plus the batch scope ('multiple ids in one call'), so the agent knows it's the multi-id variant. It does not explicitly name or contrast with the single-id siblings (ebay_live_stream, ebay_live_streams), leaving the differentiation implicit.

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?

'for multiple ids in one call' implies the use case (batch retrieval) but there is no explicit when/when-not or pointer to the single-id alternative for one-off lookups. Usage is inferable but not spelled out.

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