screen_from_url

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 does not state whether the operation is read-only, what it returns, or any side effects. The only behavioral hint is that it 'runs' a screener, leaving the agent to infer the result shape from the output schema.

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 concise, with two sentences plus a clearly formatted Args section. The primary purpose is front-loaded, and the example is placed in the parameter documentation, avoiding unnecessary verbosity.

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-parameter tool with an output schema, the description covers the essential input format and use case. It lacks explicit notes on errors, rate limits, or output behavior, but these are partially covered by the output schema and the simplicity of the tool.

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 provides only 'type: string' with no description, so the description must add meaning. It does so by specifying that the URL must be a full Finviz screener URL and gives a concrete example, which gives the agent enough to construct a valid input.

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 states a specific verb 'Run' and resource 'Finviz screener from a URL', and distinguishes itself from manual filter input by noting it replicates a custom screen from the UI. This makes the tool's purpose unambiguous and clearly differentiates it from sibling screen tools like screen_stocks.

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 explicitly states when to use this tool: when the user has built a custom screen in the Finviz UI and wants to replicate it without translating filter codes. It implies that alternatives like screen_stocks are for manual filter entry, providing clear context, though it doesn't name them explicitly.

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