Retrieve detailed metadata and filter criteria for a Yahoo Finance screener before running it, so you understand what stocks it includes. Returns JSON.
Returns detailed metadata about a specific screener including criteria. Use to understand what a screener filters before running it. Returns JSON.
| Name | Required | Description | Default |
|---|---|---|---|
| screener | Yes | Screener name to get information about |
Changes observed during successful MCP inspections.
v1.0.6Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full behavioral burden. It discloses the return shape broadly ('detailed metadata... including criteria' and 'Returns JSON'), but says nothing about permissions, error behavior when a screener name is invalid, or whether the lookup is read-only. Adequate but thin for an unannotated tool.
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?
Three short sentences with the core purpose front-loaded and no padding. The trailing 'Returns JSON' is low-value since it is the expected default for this API, but it costs almost nothing.
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 one-parameter read tool with no output schema and no annotations, the description covers purpose, intended use, and return content. The remaining gap is routing against the get_screener sibling, which is a minor omission given the tool's simplicity.
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 coverage is 100% and the single parameter is fully described in the schema ('Screener name to get information about'). The description adds no format, casing, or discovery guidance (e.g., where valid names come from, presumably list_screeners), so it does not exceed the schema baseline.
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?
Clear specific verb (returns metadata) and resource (a specific screener), with the added scope of 'including criteria'. It distinguishes itself from list_screeners by being singular and detail-oriented, though it never names the near-identical sibling get_screener, so the differentiation is implied rather than explicit.
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 sentence 'Use to understand what a screener filters before running it' gives a genuine usage context, which is more than most. However, it offers no exclusions and does not distinguish the tool from the very similar get_screener sibling, so the agent must infer which one to pick.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.