Top Movers

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

The description mentions 'correlated news reasons', which adds some behavioral detail beyond the readOnly annotation. However, it does not disclose pagination behavior (e.g., that next_params is used for paging), or any limitations or edge cases (e.g., how the standard deviation is computed, whether the list is sorted by default). Given the annotations already establish safety, the description adds modest but not comprehensive behavioral insight.

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 concise (two sentences) and front-loads the core purpose. The second sentence listing parameters is somewhat redundant but not overly verbose. It is well-structured but could have been slightly more compact by omitting the redundant parameter 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 provides the key context (unusual price movement threshold) and notes the inclusion of news reasons, but it does not explain the output structure or mention the use of pagination. Given the schema is rich and output schema exists, the missing usage guidance and pagination explanation leave some gaps, but it is not severely incomplete.

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 redundantly repeats the schema descriptions for 'markets' and 'sort' but omits any extra meaning for 'date', 'limit', and 'next_params'. It fails to clarify parameter interactions or defaults beyond what the schema already provides. Since the schema coverage is 100%, the description adds minimal semantic value.

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 function: retrieving stocks with price fluctuations exceeding the 20-trading-day standard deviation, and also mentions that correlated news reasons are included. This is specific and distinct from typical list endpoints, making the purpose unambiguous.

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 does not provide any guidance on when to use this tool compared to other market data tools, such as 'quotes', 'candlesticks', or 'rank_list'. It lacks context about scenarios (e.g., 'use this to identify unusual movers for news analysis') or prerequisites, leaving the agent to infer applicability.

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