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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds genuine behavioral value beyond that by clarifying that the lookup is not scoped to upcoming/live auctions and that ended auctions still resolve — a non-obvious trait.

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 sentences, the resource and id-key are front-loaded, and every clause earns its place by either naming returned fields or stating a scoping caveat. Zero 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?

A single-param read tool with full schema coverage, an output schema, and annotations covering safety. The description covers what the tool returns, how it is keyed, and its scope limit — nothing material is missing.

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% and the single auction_id parameter is documented with an example (e.g. 32001) in the schema itself. The description only says 'by id', adding no format or constraint detail beyond what the schema provides, so the baseline 3 is appropriate.

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 (detail/retrieve) and resource (Bonhams auction) keyed by id, and enumerates the returned fields. It implicitly distinguishes itself from bonhams_auction_search (which would be for lookup without an id) and bonhams_auction_lots (lots within the auction), though it does not name those siblings explicitly.

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 'by id' framing signals it is a lookup tool rather than a search tool, and the second sentence gives a concrete when-it-applies rule: historical/ended auctions resolve too, so the agent should not avoid it for past auctions. No sibling alternative is named, which keeps it just 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.