List Yahoo Finance industries with their keys and names, then use a returned key to retrieve details for that industry via the detail endpoint.
Yahoo Finance industries. Lists the Yahoo Finance industries, each with a key and a name. It takes no parameters. Pass a returned key to /yahoo-finance/industries/{key} for that industry's detail.
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations the description carries the full burden, and it discloses that the call takes no parameters and returns a key/name pair, plus the follow-up navigation path. It does not state read-only status or any auth/rate-limit context, but for a parameterless index listing there is little else to disclose.
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, front-loaded with the resource and return shape, then the no-parameter fact, then the next-step path. No filler.
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?
There is no output schema, so naming the returned fields is genuinely necessary and present. For a trivial zero-param lookup, nothing an agent needs in order to call it or to chain into the detail tool 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?
Zero parameters, which is the baseline 4 case. The description correctly confirms 'It takes no parameters', removing any ambiguity about whether filtering arguments exist.
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?
States a specific verb and resource ('Lists the Yahoo Finance industries') and immediately names the returned fields (key, name), so an agent knows exactly what comes back. It is clearly distinct from the ticker-level siblings.
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?
Tells the agent what to do next: pass a returned key to the industry detail path, which routes to the sibling detail tool. It does not explicitly say when to prefer this over yahoo_finance_sectors, so it stops short of full when/when-not guidance.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.