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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description adds meaningful behavioral context: values are community estimates rather than official prices)Skip; this prevents the agent from treating the result as authoritative. It also discloses the inclusion of a data-collection datecherish; with no contradiction and useful additions, this exceeds the baseline.

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 compact and front-loaded: the core purpose appears first, followed by return-value details, an application example, and an important caveat. Every sentence contributes value, and there is no redundant repetition of schema or annotation information.

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?

Given no output schema, the description sufficiently explains what the tool returns: community trade value, popularity, catalogue position, marketplace frequency, and collection date. It also manages expectations by noting that values are unofficial estimates, making the tool's behavior clear and usable without further context.

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% and both parameters are well documented in the schema. The description reinforces the item parameter with an example but does not add semantic detail beyond the schema, so the baseline score 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 states a specific verb ('look up'), a concrete resource (item value in Roblox trading games), and narrows the scope to three named games. It clearly differentiates this single-item value lookup from the sibling tools focused on checking trades, listing values, and searching items.

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 explicit use-case guidance with a concrete example question, making it clear when to invoke this tool. It does not explicitly mention when not to use it or name alternatives, but the provided application context is sufficient for an agent to route requests correctly.

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