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

Annotations already cover read-only, idempotent, non-destructive, open-world behavior. The description adds important operational context beyond that: a 5-minute result cache means the current bid can be stale, and near auction close it should be treated as a lower bound rather than the final price.

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 adds return fields, a critical pricing caveat, and cache freshness in compact form. Every sentence contributes useful information with no 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?

For a search tool with no output schema, the description explains what listings contain, how Buy-It-Now differs from sold price, and the important cache limitation. Combined with the annotations and complete schema, an agent has what it needs to invoke this tool correctly.

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 description coverage is 100%, so the schema already documents query, limit, and page thoroughly, including examples and limits. The description adds little parameter-specific meaning beyond that baseline.

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 (Search) and resource (active US ag/construction/livestock/transportation equipment auctions on bigiron.com), including the platform scope. It distinguishes itself from sold-price search by emphasizing active timed auctions and clarifying that Buy-It-Now is not a sold price.

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?

Usage is implied by 'active' auctions and the warning about Buy-It-Now not being a sold price, which helps avoid misuse for sold-price research. However, it does not explicitly name alternatives such as bigiron_sold_search or bigiron_lot_detail, nor does it state when not to use this tool beyond the broad active-vs-sold distinction.

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