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

With no annotations provided, the description carries the full burden of behavioral disclosure. It explains the scanning behavior, default mode, output contents, and the difference between auction and fixed-price results. It does not mention rate limits, failure modes, or whether the tool only returns links versus executing purchases, but the core behavior is reasonably transparent.

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 three concise sentences with no filler. The purpose is front-loaded in the first sentence, followed by mode behavior and output contents. Every sentence adds value.

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?

The tool has 6 parameters and no output schema, but the description covers the return contents (market median, percent under market, buy link) and explains the two operational modes. It is complete enough for an agent to understand what results to expect, though it could specify sorting behavior or edge cases like empty results.

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 baseline is 3. The description adds meaningful context for buying_option by explaining what AUCTION and FIXED_PRICE modes do, but it does not add significant semantics beyond the schema for the other parameters.

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 ('Scan'), resource ('live eBay listings'), and outcome ('return the ones priced furthest under the current market median'). It clearly identifies the tool's core function and distinguishes its auction vs fixed-price modes, though it does not explicitly differentiate from sibling tools like price_check or flip_margin.

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 gives clear guidance on when to use AUCTION vs FIXED_PRICE mode, which is useful context. However, it never mentions alternatives or explicitly states when NOT to use this tool over siblings like hot_list or price_check, leaving that differentiation to inference.

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