market_intelligence[$0.005 USD per call] Real-time crypto market price data
| Name | Required | Description | Default |
|---|---|---|---|
| symbol | Yes | Ticker symbol, e.g. ETH, SOL, BTC. | |
| payment | No | Optional x402 payment proof (EIP-3009 signed authorization). Call once without it to receive the payment requirements, then retry with the proof. |
Changes observed during successful MCP inspections.
Input schema / properties / symbol / descriptionPrevious value: -"Path parameter 'symbol'"New value: +"Ticker symbol, e.g. ETH, SOL, BTC."Input schema / examplesAdded value: +[
+ {
+ "symbol": "ETH"
+ }
+]Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The annotations already establish read-only, idempotent, non-destructive behavior; the description adds useful cost context ('$0.005 USD per call') and freshness ('Real-time'). This goes beyond the annotations without contradicting them.
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 a single front-loaded sentence that opens with the headline cost and states the tool's function with zero filler. Every word earns its place given that the schema handles parameter details.
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?
The tool is simple (one required parameter, strong annotations, no output schema), and the description conveys that the result is real-time market price data. It does not describe the exact output shape, but the low complexity and detailed schema/annotations make this adequate for invocation.
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%, and both 'symbol' and 'payment' are documented with meaningful detail including the EIP-3009 payment proof flow. The description itself adds no parameter-level semantics, so it meets the baseline rather than exceeding 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 identifies a concrete resource ('crypto market price data') and the 'real-time' qualifier narrows its scope. It does not use an explicit verb like 'get' or 'return', but the noun phrase is sufficient to distinguish it from siblings such as gas_oracle, nft_search, and token_security.
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 statement about when to use this tool versus the sibling tools. An agent might infer use for current prices, but the description never says when not to use it (e.g., analytics, security, deal tracking) and names no alternatives.
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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