$0.007 — Ultra-minimal Fear & Greed tick at $0.01 — value, label, and timestamp only. Keys: v=value, l=label, t=timestamp. 300s cache.
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": "fg_micro"
}
}| 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, the description carries the full burden and does reasonably well: it discloses the price, that results are cached for 300s (a meaningful staleness signal), and exactly which fields come back. It does not state the underlying data source or whether the cached value can lag the market, but for a read-only tick this is solid disclosure.
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 with no filler, and the key mapping is stated explicitly rather than left to guesswork. Leading with the price is unconventional but front-loads the differentiator this tool is sold on; nothing is redundant.
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?
Because there is no output schema, the description must define the return shape, and it does list v, l, and t. However, it omits the value's range (e.g., 0-100), the possible label strings, and the timestamp's unit or format, all of which an agent needs to interpret the response correctly.
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 takes zero parameters, so the baseline is 4; there is nothing for the description to disambiguate on the input side. It instead spends its budget on output key semantics (v/l/t), which is the more useful information here.
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 names a specific resource (Fear & Greed tick) and narrows the scope precisely with 'value, label, and timestamp only' and 'ultra-minimal'. The word 'ultra-minimal' plus the sibling-context contrast against a fuller 'fear_greed' implies differentiation, but it never names that alternative, so the distinction is inferred rather than stated.
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?
Usage is only implied through cost ('at $0.01' versus the $0.007 price) and the word 'minimal', suggesting this is the cheap lightweight option. There is no explicit statement of when to prefer this over a fuller Fear & Greed tool, and no exclusions or prerequisites are given.
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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