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

Annotations already indicate non-read-only and open-world behavior. The description adds useful context beyond that: it relies on recent real sold comps, computes a 14-day sell chance, net after eBay fees, and only produces a worth-it verdict when cost is provided. It does not mention possible credit costs or other side effects, but it does not contradict the annotations.

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 dense but efficient: one sentence enumerates the full output contract, and a second sentence gives the key input preference. There is no filler or repetition of the schema, though the long first sentence could be slightly easier to parse.

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?

With no output schema, the description does a good job of explaining what the agent will receive: estimate, range, comps, list prices, sell chance, net fees, and verdict. It also clarifies image vs description input behavior. It does not specify exact response structure or mention any credit prerequisite, but for an estimation tool it is largely complete.

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 parameters are already well documented. The description adds some practical nuance by saying to pass image_url whenever one exists and that description alone works but reads less, but it largely reinforces what the schema already states rather than adding substantial new meaning.

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 clearly states the tool's job: estimating what a secondhand item sells for on eBay US, and enumerates the specific outputs (estimate with range, comps, list prices, sell chance, net fees, verdict). This distinguishes it from siblings like get_sold_comps and worth_it, which cover only parts of this output set.

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 input guidance, such as providing image_url when available and noting that description alone works but reads less. However, it does not explicitly state when to choose price_item over sibling tools like get_sold_comps or list_on_ebay, so the selection context is implied rather than fully specified.

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