Fetch trending stock symbols from Yahoo Finance by region and set count to control how many to return.
Yahoo Finance trending symbols. Returns the symbols Yahoo Finance lists as trending in a region such as US. count sets how many. The response has region, count, the symbols, and the job_timestamp and start_interval fields.
| Name | Required | Description | Default |
|---|---|---|---|
| count | No | Symbol count | |
| region | Yes | Region such as US |
Changes observed during successful MCP inspections.
v1.0.0Does 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 does disclose the response shape including job_timestamp and start_interval, which hints that the data is job-cached rather than live, and implicitly frames this as a read. It does not state auth needs, rate limits, or how fresh the trending list is.
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 tight sentences with the purpose front-loaded, followed by parameters and then return fields. No filler, though the parameter and response sentences partially duplicate what the input schema already says.
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?
With no output schema, the description usefully enumerates the returned fields (region, count, symbols, job_timestamp, start_interval), and the input schema is self-documenting. For a simple two-parameter read tool the definition is nearly complete; the missing piece is routing guidance among the many sibling trending/finance tools.
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 schema already documents both parameters. The description's 'region such as US' and 'count sets how many' simply restate the schema descriptions verbatim, adding no format, default, or range detail. Baseline 3 applies.
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?
Specific verb (returns) plus resource (trending symbols) with a clear scope: symbols Yahoo Finance lists as trending in a region. An agent can tell this is a trending-list tool within the yahoo_finance family. It does not, however, distinguish itself from adjacent trending tools such as google_finance_markets_trending or coingecko_trending.
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 explains what the tool returns but gives no when-to-use guidance, no prerequisites, and no alternatives. Despite an enormous sibling set containing several other trending tools, it never says why an agent should pick this one instead of a finance quote, screener, or competitor trending feed.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.