Xynaptic Security Price — spot market data for US stocks: price, previous close, day range, 52-week range, currency, exchange + up to 30d history (OHLCV). GET ?ticker=AAPL&history=30. Refreshed intraday. [price: $0.010 per call, x402/USDC]
| Name | Required | Description | Default |
|---|---|---|---|
| params | No | query parameters |
Changes observed during successful MCP inspections.
Input schema / properties / bodyRemoved value: -{
- "description": "JSON body for POST endpoints (e.g. insurance, ai-chat, production-risk)",
- "type": "object"
-}Input schema / properties / params / descriptionPrevious value: -"query parameters, e.g. {city: 'Paris', type: 'Appartement'}"New value: +"query parameters"Input schema / properties / params / propertiesAdded value: +{
+ "previous_close": {
+ "description": "example: 336.13",
+ "type": "number"
+ },
+ "price": {
+ "description": "example: 341.07",
+ "type": "number"
+ },
+ "ticker": {
+ "description": "example: \"AAPL\"",
+ "type": "string"
+ },
+ "week52_high": {
+ "description": "example: 345.34",
+ "type": "number"
+ },
+ "week52_low": {
+ "description": "example: 169.21",
+ "type": "number"
+ }
+}Input schema / requiredAdded value: +[]Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden and discloses meaningful behavioral traits: the endpoint is a GET (implying a safe read-only operation), data is refreshed intraday, up to 30 days of OHLCV history are available, and each call costs $0.010 via x402/USDC. It does not spell out rate limits or error behavior, but for a read-only market-data endpoint the cost, refresh cadence, and HTTP method are the most decision-relevant details.
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, dense sentence with the tool name and primary purpose front-loaded, followed by returned fields, request format, refresh note, and cost. Every clause contributes relevant information, though the bracket notation for pricing is slightly compressed rather than fully structured.
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?
With no output schema or annotations, the description does the heavy lifting by listing the returned data fields, specifying the history range, noting intraday refreshes, and stating the call cost and payment protocol. It omits error handling and rate limits, but for a spot price and short-history endpoint the description provides enough for an agent to invoke it 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?
Schema coverage is 100%, but the nested parameter descriptions are only example values, not semantic documentation. The description adds value by showing the exact query format (GET ?ticker=AAPL&history=30) and introducing a history parameter not present in the schema, clarifying that up to 30 days of OHLCV data can be requested.
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 the specific resource (spot market data for US stocks) and enumerates the exact fields returned: price, previous close, day range, 52-week range, currency, exchange, and up to 30d OHLCV history. It distinguishes itself from siblings like security-eu-price (EU scope) and security-technical (technical analysis vs raw spot data) through the explicit 'US stocks' and 'spot market data' framing.
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 defines what the tool provides and includes a concrete request example (?ticker=AAPL&history=30), which implies usage for fetching US stock spot prices and short-term history. However, it does not explicitly state when to prefer this over alternatives such as security-technical, security-eu-price, or security-fundamentals, leaving the agent to infer the scope from the field list.
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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