discovery

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

Annotations already provide readOnlyHint, openWorldHint, and idempotentHint. The description adds context about the tool's behavior: it returns lists and screens, and does not require tickers or countries. This supplements the annotations without contradiction.

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?

Description is two paragraphs: first explains the tool's purpose, second lists indicators. It is front-loaded with the main idea. Could be slightly more concise by merging the indicator list into the first sentence, but remains efficient.

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?

The description explains what kind of data is returned and that no tickers are needed. However, with 13 parameters, many generic filters, it does not clarify which filters are applicable to which indicators or how they interact. The output schema exists but is not described, so behavior is partially clear but incomplete.

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?

Input schema coverage is 100%, but parameter descriptions are mostly tautological (e.g., 'Value for beta_lower'). The description lists the indicator enum values, which adds some context, but does not explain how parameters like beta, price, or volume relate to each indicator. No additional meaning beyond schema defaults.

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 it is a market discovery tool providing lists of stocks/ETFs/cryptocurrencies, stock screener, gainers, losers, sector performance, and earnings/dividend calendars. It distinguishes from sibling tools by noting 'No tickers or countries needed,' which implies it is for broad market overviews without requiring specific identifiers.

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 for discovering market data without tickers or countries, but does not explicitly state when to use this tool versus sibling tools like search_instruments or search_by_category. It mentions available indicators but lacks guidance on when to choose one indicator over another.

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