Top Movers

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

With no annotations provided, the description carries the full burden of behavioral disclosure and does so reasonably well. It explains that gainers and losers rank by percent change, notes that untraded shares are excluded rather than shown as losses, and defines the meaning of the direction parameter. It does not mention rate limits, authentication, or exact output contents, but the output schema covers the return structure.

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 compact and front-loaded with the core purpose, followed by two sentences that add meaningful ranking and exclusion behavior. Every sentence earns its place, and there is no redundant filler or repetition of the tool name.

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 simple query tool with an output schema, the description covers the key invocation details: the supported direction values, the ranking basis, and the handling of untraded shares. It does not document possible exchange identifiers or limit constraints, but the defaults in the schema and the self-explanatory parameter names reduce the practical gap. The main missing element is usage routing relative to sibling tools, which is already penalized under usage guidelines.

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 compensate for missing parameter documentation. It thoroughly explains the 'direction' parameter, including its valid values and ranking semantics, but it does not explain 'limit' or acceptable 'exchange' values beyond the default in the schema. The parameter names are self-explanatory, but the description only partially bridges the schema's lack of documentation.

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 identifies the resource as the session's biggest movers on one exchange, which is specific enough to distinguish the tool's subject matter from siblings like market_summary or compare_exchanges. However, it lacks an explicit verb such as 'List' or 'Get,' and it does not directly differentiate itself from sibling tools by name.

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 explains what the tool returns and clarifies the 'direction' values, but it provides no guidance on when to use this tool versus alternatives. There are no explicit when-to-use or when-not-to-use conditions, nor any mention of sibling tools like market_summary for broader market context or compare_exchanges for multi-exchange comparisons.

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