Top Movers

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

With no annotations, the description carries the behavioral burden. It discloses the circuit-breaker rule for gainers/losers and the live-quote/turnover logic with untraded instruments excluded, which are non-obvious data behaviors. It does not detail ordering or output size, but an output schema exists and these are minor gaps.

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?

Two compact sentences front-load the parameter value list and add only essential behavioral detail. No filler or repeated schema information.

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 single optional parameter with an output schema, the description provides everything needed to call the tool: possible values and special calculation rules. The default value is already in the input schema, so no duplication is needed.

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 coverage is 0%, so the description must define the category parameter. It enumerates all four valid values and explains the conceptual difference between the gain/loss lists and turnover leaders. This fully compensates for the empty schema description.

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 says the tool returns top movers and enumerates the four category values, making the resource and scope identifiable. It lacks an explicit action verb and does not name sibling tools, but the category list strongly distinguishes it from tools like market_summary and sector_performance.

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 category values and their meanings make it clear that this tool is appropriate when an agent needs top movers by one of the listed metrics. It does not explicitly say when to choose this over siblings like market_summary or get_quote, nor does it mention exclusions.

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