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

With no annotations, the description carries the full burden. It usefully discloses data provenance (operator's own eBay shop, real completed transactions) which tells the agent the data is authoritative and read-only in effect. It says nothing about result count, pagination, latency, or auth needs.

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?

One sentence, front-loaded with the resource and immediately qualified by scope. Every clause earns its place; nothing is padded.

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 one-parameter read tool with no output schema, the description covers what the tool returns and where the data comes from, which is the key ambiguity. It could still say whether the result is a list or aggregate and how many sold records are returned.

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?

There is a single parameter, q, and schema description coverage is 100% ('The item'). The description adds no syntax, matching, or format guidance beyond what the schema already states, so the baseline 3 applies.

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 resource (sold prices for an item) and pins down scope precisely: the operator's own eBay shop, actual transactions rather than asking prices. This differentiates it from generic price-lookup data, though it never names or contrasts with the siblings get_worth, get_history, or check_deal.

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 phrase 'not asking prices' implies a contrast with asking-price tools such as get_worth, but the alternative is never named and no condition for choosing this tool over its three siblings is given. Usage must be inferred from the data-source hint alone.

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