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

With no annotations, the description carries the full burden, and it does add two useful behavioral facts: only 'active' listings are returned, and each record costs 1 point (a credit-cost disclosure that matters for budgeting). It still omits pagination behavior, rate limits, and what happens when max_items/start_page exceed the seller's inventory.

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?

Two short sentences, front-loaded with the action and scope, with the cost note kept to a single clause. Nothing is padded, though the payoff on the second sentence is modest.

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 3-parameter, no-annotation, no-output-schema tool this covers the essentials plus return fields and cost. However, it leaves pagination semantics and the relationship between start_page, max_items, and credit spend unexplained, which an agent needs to page 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?

Schema description coverage is 100%, so seller, max_items, and start_page are already fully documented, making 3 the baseline. The description adds only the tangential cost linkage ('1 point per returned record') without clarifying how max_items and start_page interact with that cost or with result ordering.

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 and resource ('List active eBay listings for a seller') and enumerates the returned fields, so an agent immediately knows what it retrieves. It does not explicitly distinguish itself from close siblings like run_ebay_seller (seller profile) or run_ebay_item_search, but the seller-scoped listing scope is clear enough to separate it in practice.

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 when-to-use guidance, no mention of prerequisites, and no routing to alternatives such as run_ebay_item_search (search by keyword) or run_ebay_seller (profile data). The agent must infer from the name alone which eBay tool fits a given request.

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