indices_gainers

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

With no annotations provided, the description must convey behavioral details on its own. It only states a noun phrase without any disclosure of output format, sorting order, time period, pagination, or limitations. The agent knows it returns something, but has no clue about the structure or behavior of the response, making it significantly under-transparent for a zero-annotation tool.

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, direct sentence with no filler or repetition. It is front-loaded with the action and resource, making it easy to parse. However, the extreme brevity borders on under-specification rather than elegant conciseness, so it earns a 4 rather than a 5.

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?

Despite low complexity (no params), the absence of an output schema and any annotation means the description must stand alone to guide the agent. It fails to explain what 'gainers' entails (e.g., sorted by percentage change, limited to top N), or what the return structure looks like. Given the large sibling family, more context on the typical response (e.g., a list of index symbols with performance) is expected for a complete definition.

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?

Since the tool has zero parameters and the schema already covers 100% (empty object), the description need not explain params. Per guidelines, 0 params yields a baseline of 4. The description adds nothing about params, but none are needed, so the score holds.

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 'Get top index gainers' specifies a clear verb and resource, indicating it retrieves top-performing indices. It distinguishes itself from other gainer tools (e.g., etf_gainers, stocks_gainers) by the explicit 'index' term, and from indices_losers by 'gainers'. However, it does not explicitly name an alternative, so it lacks the strongest differentiation seen in top-tier descriptions.

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 provides no guidance on when to use this tool versus sibling tools like etf_gainers or crypto_gainers. It does not state conditions, exclusions, or alternatives. An agent would have to infer that the 'indices' prefix indicates the intended asset class, but no explicit steering exists.

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