Wicked MCP server

rates

Read-onlyIdempotent

Fetch US Treasury yield curve data from FRED, including 1M–30Y maturities and 10y-2y and 10y-3m recession spreads for fixed-income analysis.

Instructions

[Trading Data API] US Treasury yield curve (1M–30Y) + recession-indicator spreads (10y-2y, 10y-3m), from FRED.

Example: /v1/rates

Use when you need the US Treasury yield curve and recession spreads (10y-2y, 10y-3m). Not for event dates (use macro_calendar).

Behavior: read-only. Priced via x402 (USDC on Base) or free with WICKEDAPI_API_KEY; with neither, you get HTTP 402 with the decoded price in payment_required (a price quote, not a failure).

Tool call template

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": "rates"
  }
}

Input Schema

Name	Required	Description	Default
`series`	No	Optional. A specific FRED series id (e.g. DGS10) for a single value.

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.3.1Oct 3, 2026

TDQS

A4.3/5.0

Behavior4/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint/idempotentHint/destructiveHint, so the 'read-only' note mostly repeats them. However, the description adds genuinely valuable context beyond annotations: pricing via x402 (USDC on Base) or API key, and the crucial disclosure that a 402 response is a price quote, not a failure.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loaded with the resource and scope, then usage, then behavior, with a concrete example endpoint. Minor waste in restating 'read-only' already covered by annotations, but otherwise tight.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a one-optional-param read tool with no output schema, the description covers purpose, routing, and the payment/auth behavior that would otherwise confuse an agent. Return payload shape is undescribed, but that is a minor gap given the tool's simplicity.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% and the single 'series' parameter is fully documented in the schema. The description adds no parameter guidance, so the baseline 3 for a schema-documented tool is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific resource (US Treasury yield curve 1M–30Y) plus the recession spreads (10y-2y, 10y-3m) and the data source (FRED). It names the sibling it is not (macro_calendar), so an agent can distinguish it without opening the schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines5/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly states when to use it ('when you need the US Treasury yield curve and recession spreads') and when not to, routing event-date needs to macro_calendar. Nothing is left to inference.

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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