Get major market indices and macro indicators: S&P 500, NASDAQ, VIX, 10-Year Treasury, WTI Oil, Gold, USD/EUR. Data from FRED (St. Louis Fed).
This tool declares no required parameters. Add optional parameters from the input schema as needed.
{
"id": 1,
"jsonrpc": "2.0",
"method": "tools/call",
"params": {
"arguments": {},
"name": "get_market_indices"
}
}| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries full behavioral disclosure burden. It adds value by naming the data source (FRED), but it does not mention response format, update frequency, rate limits, or any other traits. The simple getter nature is clear, but additional context would be beneficial.
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 two sentences, front-loaded with the purpose and then the source. Every word earns its place, delivering maximum information in minimal space.
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 zero-parameter retrieval tool with no output schema, the description is sufficiently complete: it lists all expected data items and the source. It could optionally note whether data is real-time or delayed, but that is not critical for basic usage.
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 tool has zero parameters, so the schema imposes no burden. The description compensates by listing the specific indicators returned, giving the agent a clear idea of what the output covers. Baseline for 0 params is 4, and the description meets it.
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 clearly states the tool's purpose with a specific verb ('Get') and explicitly lists the resources (S&P 500, NASDAQ, VIX, etc.). This distinguishes it from siblings like get_stock_quotes (individual stock prices) and get_institutional_holdings (holdings data).
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 implies its use case by enumerating macro indicators and indices, which differentiates it from stock-specific queries. However, it does not explicitly state when to use this tool versus alternatives or provide any exclusion criteria.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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