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

With no annotations provided, the description carries the behavioral burden, and it delivers useful semantic detail: it explains the two ranking dimensions and illustrates the difference between total copies and unique owners with a concrete example. It does not cover operational behavior like response shape or defaults, but the key aggregation behavior is 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?

Three purposeful sentences: the first states the scope, the second positions the tool against price/sales signals, and the third clarifies ranking semantics with a memorable example. There is no filler or repetition of schema details.

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 concept well enough to choose and call the tool, but it omits what the response contains structurally and does not mention filtering or pagination behavior. Since there is no output schema and no annotations, the absence of a clearer result contract leaves an agent with some uncertainty.

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 description adds meaning to the kind and sort parameters by explaining what 'items'/'creators' and 'total_copies'/'unique_owners' represent, and the example maps directly to the sort enum. However, schema coverage is only 50%, and limit, offset, and direction receive no added context beyond their bare schema definitions, so the compensation is incomplete.

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 names the exact resource—Limiteds and creators held across the portfolios RBX Invest tracks—and defines a clear scope. It also distinguishes this tool from price or sales-volume signals, which separates it from sibling tools like get_market_stats or get_item_details without being tautological.

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 a clear usage context: use this when you care about what people chose to keep rather than what a thing trades at. It does not explicitly name alternative tools or state when not to use it, so it stops short of full routing guidance.

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