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

Annotations already establish readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is fully covered. The description adds genuine behavioral context beyond that: the slug is effectively a placeholder that is ignored when auction_id/lot_no match, and it discloses what data the call returns. No contradiction with 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?

Two sentences with zero waste: the first front-loads what the tool returns, the second states prerequisites and the slug nuance. Every clause earns its place, and the most decision-relevant information (what it does, what it needs) appears first.

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?

There is no output schema, so the description carries the burden of explaining return values — it does so thoroughly by enumerating six concrete data categories. Given only 3 parameters (all documented in schema) and strong safety annotations, nothing critical is missing for calling the tool. Minor gaps are the absence of error/not-found behavior and price currency, but these are not blocking for a simple single-lot fetch.

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 all three parameters are already documented in the input schema — the baseline is 3. The description adds value beyond the schema by tying auction_id/lot_no to their provenance in bonhams_results_search and by clarifying the matching condition that governs whether the slug matters. This cross-tool dependency information is not present in the schema itself.

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 states a specific verb and resource ('Full detail for one Bonhams lot') and enumerates the exact payload: description, condition, images, realized price (hammer + buyer's premium), estimate range, and sale date. It implicitly distinguishes itself from the sibling bonhams_results_search by positioning itself as the detail companion to that search tool. An agent can tell exactly what this tool returns without opening the schema.

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 names the prerequisite workflow explicitly: 'Needs the auction_id and lot_no from bonhams_results_search', telling the agent to search first and then fetch details. It also gives direct parameter-usage guidance for the optional slug ('any slug works as long as auction_id/lot_no match'). It stops short of stating explicit when-not-to-use conditions or naming a full alternative, so slightly below a 5.

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