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

Annotations already flag the tool as read-only, idempotent, and non-destructive. The description adds value by specifying that closed=true returns ended listings, that output includes total match count plus specific listing fields, and that eBid is a small marketplace. No contradiction with annotations; no rate-limit or auth caveats are disclosed, but the schema already documents optional API-key behavior.

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 efficient and well-structured: four sentences cover action, filters, the key closed/live behavioral distinction, return shape, and a market caveat. Important information is front-loaded 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?

Given 15 optional parameters and no output schema, the description provides enough invocation context: it lists return fields, explains the closed-search behavior, and qualifies the data source. The schema handles parameter details. A minor gap is not explicitly routing users to sibling tools for listing details or category browsing, but this is not a blocker for correct invocation.

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 coverage is 100%, so the baseline is 3. The description adds semantic value by grouping filters (keyword, category, price range, condition, buy-now, seller, country), and by explaining why closed=true matters for realized sale prices. This goes beyond the schema's straightforward 'true = search ONLY closed' wording.

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 verb-resource pair: 'Search listings on the eBid.net online marketplace and auction site.' It also distinguishes this tool from siblings like ebid_categories, ebid_listing, and ebid_listing_bids by emphasizing search behavior, filters, and returned listing-level data. The closed=true clarification further differentiates live-search from ended-listing search.

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 gives clear contextual guidance: closed=true should be used to find realized sale prices in ended listings, and results should be treated as a secondary price source. It does not explicitly name sibling alternatives or state when not to use this tool, but the context is strong enough for an agent to make a reasonable selection decision.

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