Fetch Yahoo Finance market summary rows for a specified market, like US, returning instruments with symbols and short names for quick review.
Yahoo Finance market summary. Returns the market summary rows for a Yahoo Finance market such as US, as a summary list of instruments, each with fields such as symbol and shortName.
| Name | Required | Description | Default |
|---|---|---|---|
| market | Yes | Market 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 burden. It does usefully disclose the return shape ('summary list of instruments, each with fields such as symbol and shortName'), which matters because there is no output schema. However, it says nothing about pagination, whether this is a snapshot or streaming, authentication, or rate limits, so behavioral coverage is partial.
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?
Two compact sentences, front-loaded with purpose and followed by return shape. Every clause carries information; only the redundant repetition of the 'market' example slightly dilutes it.
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 and return fields adequately. What it omits is guidance on valid market values and how it differs from the other market-level Yahoo Finance tools, but nothing essential to invoking it is missing.
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% for the single 'market' parameter, so the schema already documents it. The description repeats the same 'market such as US' example found in the schema and adds no syntax, enumeration, or valid-value guidance beyond it. Baseline 3 is appropriate.
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 ('Returns') and resource ('market summary rows for a Yahoo Finance market') with a concrete example ('US'). It is clear what the tool does, but it does not differentiate itself from closely named siblings like yahoo_finance_market_status or yahoo_finance_trending, leaving the agent to guess which market-level tool to pick.
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?
There is no when-to-use guidance, no mention of prerequisites, and no reference to alternatives such as yahoo_finance_market_status or yahoo_finance_screener. The agent is given the what but not the when.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.