Auction outcome and final price

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

Annotations already declare readOnlyHint, openWorldHint, and idempotentHint. The description enriches this by disclosing that in-progress auctions return 'in_progress' rather than failing, winner identities are redacted, bid amounts appear only after conclusion, and attemptNumber indicates prior sale failures. These are meaningful behavioral details beyond the annotations.

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 organized into clear sections (intro, WHEN TO USE, KEY PARAMETERS, EXAMPLE, RETURNS), with the most important information front-loaded. It is somewhat lengthy, but every section contributes useful detail, so it earns a 4 rather than a 5.

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 no output schema, the description takes on the burden of explaining return values. It enumerates possible outcome values, starting vs final price with priceUpliftPercent, bid/disqualified-bid counts, attemptNumber, awards, contracts, and cancellation reasons. It also covers platform redaction and timing of bid amounts. This is thorough for a single-parameter tool.

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 input schema already provides 100% coverage for the single 'auction' parameter, including format examples. The description's KEY PARAMETERS section largely repeats this ('public auction id or 24-character procedure id') and adds only a concrete example. This aligns with the baseline of 3 for high schema coverage; it does not add meaningfully new semantics.

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 opens with a clear, specific verb+resource: 'How one auction ended: sold or not, for how much, to how many bidders.' This directly states what the tool returns and distinguishes it from siblings like get_auction (likely auction details) and get_auction_timeline (event history). The addition of in-progress auctions further refines the scope.

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 'WHEN TO USE' section provides explicit example queries: 'what did it go for', 'did it sell', 'how many people bid', 'why was it cancelled'. This gives clear usage context. However, it does not name alternative tools or explicitly state when not to use this tool, so it falls short of a 5.

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