etf_losers

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It only says 'Get', implying a read operation, but does not mention what the response looks like, whether results are sorted, if there is a limit, or any details about the data returned. The description adds no behavioral context beyond the obvious read nature.

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, front-loaded sentence with no superfluous words. It is highly concise, but could be slightly more detailed in explaining the ranking criteria without sacrificing brevity. Still, for a simple tool, this level of conciseness is appropriate.

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 tool is simple with no parameters and no output schema, so the description need not explain return values in depth. However, the term 'top' is ambiguous without defining what makes an ETF a 'loser' (e.g., worst performance by percentage). The description is adequate for a basic getter but lacks clarity on the exact selection criteria, leaving room for misinterpretation.

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?

There are zero parameters, and the schema is already complete (100% coverage) with no fields. Per the rubric, a baseline of 4 applies when there are no parameters. The description does not need to explain parameters, and it adds no misleading information.

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 verb 'Get' and the resource 'top ETF losers', which distinguishes it from siblings like etf_gainers and crypto_losers by asset class and direction. It does not specify the ranking criteria (e.g., percentage decline, dollar change), leaving some ambiguity but still conveying the core function.

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?

There is no guidance on when to use this tool versus alternatives. With many sibling tools like stocks_losers and crypto_losers, the description should explicitly state that this is for ETFs specifically, and suggest alternatives for other asset classes. The absence of any such comparison leaves the agent to infer usage from the name alone.

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