stock_screener

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. It adds valuable context beyond the schema, such as the liquidity ordering of universe files ('first N are the tradeable ones') and the currency clarification for min_price ('IDR for IDX'). It does not explicitly state that the operation is read-only, but this is implied by the screener nature, and the description does not mislead.

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 tight docstring with a single introductory sentence followed by a structured Args list. Every line adds value, and the formatting is easy to scan. There is no fluff or repetition of schema details. It is concise without sacrificing clarity.

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?

Given the moderate complexity (6 optional params, no enums, output schema exists), the description covers all core aspects: purpose, parameter semantics, and a subtle insight about universe ordering. It does not discuss edge cases (e.g., both min and max set, invalid universe) or error behavior, but for a simple screener and with an output schema present, it is nearly complete. Minor gaps prevent a 5.

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?

The schema has zero descriptions, so the description's parameter explanations are essential and richly informative. Each parameter is explained with concrete details: universe's allowed values and ticker counts, min/max change semantics, min_price's currency caveat, max_symbols' liquidity logic, and limit's row-count purpose. This goes far beyond the bare schema.

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 opens with a specific verb 'Screen' plus a clear resource ('a stock universe') and scope ('on today's move'). This clearly distinguishes it from sibling tools like crypto_screener (different asset class) and technical_scan (different methodology). The purpose is unambiguous and immediately actionable.

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 when to use this tool (when you need to screen stocks by price/change criteria) but provides no explicit guidance on when not to use it or what alternatives to consider. There is no mention of sibling tools like market_snapshot or technical_scan, leaving the agent to infer the appropriate context. This is adequate but not explicit.

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