fmp_market_movers

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

With no annotations provided, the description must convey behavioral context. It clearly indicates the tool returns market mover data, but provides no detail on data freshness, pagination, or market coverage. For a read-only data retrieval tool, this is acceptable but not outstanding. The description doesn't contradict any annotations, but it also doesn't add much beyond what the name and schema suggest.

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 sentence with 12 words, perfectly concise and front-loaded. It uses a list format that maps directly to the enum values, making it highly skimmable. Every word earns its place with no redundancy or fluff.

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 tool with a single optional parameter and no required fields, the description is largely sufficient. It covers the main use case, and the enum values are self-explanatory. However, the output schema exists but is not examined, and the description could have noted that this tool is for real-time market data as opposed to historical (which is covered by fmp_historical_prices). Overall, it's adequate but not exhaustive in guiding an agent on all edge cases.

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%, meaning the description provides no parameter-level details. However, the sole parameter 'kind' has an enum with self-explanatory values ('gainers', 'losers', 'actives') that are clearly listed in the schema. The description's phrase 'biggest gainers, biggest losers, or most actively traded' exactly mirrors the enum values, adding no extra meaning beyond the schema. Given that the schema alone fully explains the parameter, the description adds minimal semantic value beyond what's already present.

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 'Today's biggest gainers, biggest losers, or most actively traded names' clearly states the tool's purpose with specific verbs and resource types (market movers). It differentiates from siblings like fmp_screener or fmp_quote, though it doesn't explicitly name alternatives. The description is concise and informative, though it could have been more tied to the exact enum values.

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 implies usage context (to get market movers), and the parameter enum values ('gainers', 'losers', 'actives') are self-explanatory. However, no explicit when-to-use vs. alternatives is provided. Since this is a simple tool with obvious use cases, the implied guidance is adequate, but it doesn't explicitly state when not to use it or suggest alternatives.

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