yfinance_screen

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering safety traits. The description adds capability scope (predefined keys and custom query trees) but not behavioral nuances such as response size limits or pagination behavior. Since annotations carry the safety burden, a 3 is appropriate.

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 two sentences, front-loaded with the primary action and immediately followed by the key distinction between predefined and custom queries. No filler or redundancy, earning a top score.

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 tool's moderate complexity (9 parameters) but rich schema (100% param coverage) and presence of an output schema, the description is sufficiently complete. It covers the core purpose and the two query modes, though it omits nuanced guidance like when to use count vs. size, which the schema already covers. This is above average but not exhaustive.

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 100%, so the baseline is 3. The description adds a high-level note about query being either a predefined key or a query tree, but this only lightly supplements the schema's already detailed parameter descriptions for query and query_type. It does not explain interactions between size/count or sort fields.

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's function with a specific verb and resource: 'Run a Yahoo Finance screener query.' It further distinguishes itself from siblings like yfinance_screen_gappers and yfinance_get_top by mentioning support for both predefined screener keys and custom query trees, which is this tool's unique scope.

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 context by stating it supports predefined and custom queries, but it does not explicitly say when to use this tool over alternatives like yfinance_screen_gappers or yfinance_get_top. No exclusions or alternative tool references are provided, so guidance is only implied.

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