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 only 'normalized' as behavioral color and says nothing about auth needs, rate limits, or how pagination interacts with the facet-driven filtering. With annotations carrying the load, 3 is appropriate.

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 tight sentences: purpose and scope first, then sibling routing. No filler, and the most decision-relevant content (which sibling to use) is front-loaded.

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?

An output schema exists so return values need no explanation, and annotations cover safety; the description supplies purpose and routing. The only residual gap is that 'optionally filtered' contradicts the schema's required list, which could mislead an agent about whether q and department can be omitted.

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 every parameter is already documented in the schema, which sets the baseline at 3. The description reinforces that department/text filtering is optional, but this actually conflicts with the schema listing q and department as required, so it adds as much ambiguity as clarity.

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?

Specific verb ('Fetch') plus resource ('normalized lots') plus scope ('from one Bonhams auction'), with optional filters named. It also distinguishes itself from the two closest siblings by name, so an agent can route without opening a 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?

Explicitly names the alternatives and the condition selecting each: bonhams_lot_search for cross-sale lot discovery, bonhams_auction_detail for the sale itself, and this tool for lots within one auction. That is a complete when/when-not map.

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