get_market_movers

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

No annotations are provided, so the description carries the burden. It discloses the cap of 50 and that 'top' returns 'each' (gainers and losers), and adds a caveat about the data's nature. But it does not describe pagination, sorting, or what happens with no arguments, though an output schema 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 short and well-structured: a one-line purpose, a relevant caveat, and a clear args section. Every sentence earns its place, and it is front-loaded with the main action.

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 tool with one parameter and an output schema, the description covers purpose, parameter semantics, and a key behavioral caveat. It lacks explicit alternative references but is otherwise complete for the tool's complexity.

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%, but the description compensates by explaining 'top' as 'How many of each to return, capped at 50,' adding meaning beyond the raw schema fields. This is sufficient for the single parameter.

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 returns today's largest percentage gainers and losers, which is a specific verb+resource+scope. It distinguishes from siblings like get_most_active by focusing on percentage moves rather than volume or activity.

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 offers context with 'A starting list, not a signal' and notes that large single-day moves are already priced, implicitly warning against overuse. However, it does not name alternative tools or explicitly state when to use this versus another tool.

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