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

Beyond the annotations (readOnly, idempotent, non-destructive), the description adds significant behavioral detail: it explains what counts as a comp, that closed lots with no bids are excluded, that only sales above zero are counted, and that Pipeworx retains data others do not. This gives the agent a precise model of how the tool behaves.

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 front-loaded with the core purpose, then use cases, then filters and return shape, then an important inclusion boundary. Every sentence contributes meaningful information without redundancy or filler, making it information-dense yet readable.

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 there is no output schema, the description adequately covers what the tool returns (count, min/median/average/max final price, and recent examples). It explains the input filters, the inclusion rule, and the market context, giving the agent enough to know when and how to invoke it without ambiguity.

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 schema already documents all five parameters. The description adds value by providing realistic keyword examples and a critical caveat that commercial and government prices differ materially, encouraging the agent to split by segment when relevant. This goes slightly beyond the bare schema.

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: it returns historical SOLD prices (final hammer price of closed lots) for US auction items. It clearly distinguishes this tool from sibling auction tools by emphasizing that it covers sold/closed lots with recorded prices above zero, which no upstream site keeps.

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 explicitly tells the agent when to use it: to answer what used items actually fetch at auction or to comp an asset before bidding. It gives useful contextual boundaries (commercial vs. government, closed lots only) but does not explicitly name sibling alternatives such as us_auctions_search or us_auctions_closing_soon, leaving some differentiation implicit.

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