where_to_buy

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

The description discloses a key behavioral trait: the jump-distance feature only works 'when logged in', implying an authentication requirement. However, it does not mention other behaviors such as error handling for invalid item names, data freshness, or whether the tool is read-only. With no annotations provided, the description carries the full burden but only partially fulfills it.

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 a single, reasonably concise sentence that packs the main action, the list of hubs, the conditional feature, and the intended benefit. It is front-loaded with the verb 'compares' and remains readable without excessive fluff, though the final clause could be trimmed without losing essential meaning.

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 description explains the core functionality and the conditional feature, giving a clear sense of what the tool returns: a comparison of sell prices across hubs and, when logged in, jump distances. With no output schema, it does not specify the exact return format, but it is adequate for a simple single-parameter tool.

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?

The input schema already provides a clear description for the single parameter (item_name) with an example. The tool description merely references 'an item' without adding new formatting or constraint details beyond the schema, so it does not go beyond the schema. Since schema coverage is 100%, the baseline of 3 is appropriate.

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 purpose: comparing an item's cheapest sell price across five specific trade hubs, with an optional jump-distance feature when logged in. It uses the specific verb 'compares' and identifies the exact resource and scope, distinguishing it from sibling tools like lookup_item or system_intel.

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 implies this tool is for deciding where to buy an item by weighing price against haul distance, but it does not explicitly state when to use it over alternatives or mention any exclusions. The phrase 'so you can weigh price against the haul' suggests a use case, but there is no direct comparison to sibling tools or conditions like 'use this if you need the cheapest hub'.

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