top_gainers

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

The description adds valuable behavioral context: it specifies the return format (list[dict] on success) and the structured error envelope with retryable flag, which is not covered by annotations. Since readOnlyHint is true and destructiveHint is false, the safety profile is already clear, but the error handling detail goes beyond annotations. No contradiction exists.

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 well-structured with a docstring format: purpose first, then Args, then Returns. It is concise yet covers all essential details without unnecessary fluff. The structure is easy to scan, and the purpose is front-loaded.

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?

For a read-only screener, the description covers all necessary aspects: parameters, valid values, return type, and error behavior. The existence of an output schema is indicated, but the description still explains the return shape, which is helpful. No critical information is missing for an agent to call it correctly.

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 0%, so the description must fully compensate. It excels by listing valid exchange names (KUCOIN, BINANCE, etc.), valid timeframes (5m, 15m, 1h, etc.), and the limit parameter with a max of 50. This provides all necessary semantics that the schema lacks (which only has defaults and types).

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 it returns top gainers for an exchange and timeframe using Bollinger Band analysis. This distinguishes it from siblings like top_losers (opposite direction) and bollinger_scan (likely a broader scan), even though it doesn't name them explicitly. The verb and resource are specific and 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 explicitly state when to use this tool versus alternatives like bollinger_scan or top_losers. Usage is implied by the name and purpose, but no explicit conditions or comparisons are given. An agent could infer that it's for quick gainers screening, but the lack of explicit guidance leaves some ambiguity.

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