Time series of the kimchi premium from the continuous archive, both bases, newest-last. Params: ?symbol=BTC &window=1h|6h|24h|7d|30d|90d &points=500 (max 2000). Archive depth is reported as first_recorded. Costs $0.08 in USDC per call, settled via x402.
| Name | Required | Description | Default |
|---|---|---|---|
| points | No | Max points returned (default 500, max 2000) | |
| symbol | No | Archived tickers: BTC, ETH, XRP, SOL, DOGE, USDT | |
| window | No | Lookback window (default 24h) |
Changes observed during successful MCP inspections.
Input schema / properties / beforeRemoved value: -{
- "description": "Unix-second cursor from next_before; returns older rows strictly before it",
- "type": "integer"
-}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the behavioral burden and does useful work: it discloses ordering, archive-depth reporting via first_recorded, and a per-call cost settled via x402. It does not describe response shape or rate limits, but it provides meaningful behavioral context beyond a bare 'history' statement.
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 compact and front-loaded: core behavior first, then parameters, then archive-depth and cost details. Every sentence contributes useful information without filler or repetition.
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 read-only historical data tool with three optional, fully documented parameters, the description covers the essential invocation details, ordering, archive depth, and cost. The absence of an output schema makes a return-format example desirable, but the core contract is sufficiently complete for correct 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%, so the baseline is 3. The description restates the defaults, max points, and enum values in a compact query-string example, but adds little semantic meaning beyond what the input schema already provides.
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 identifies the tool as returning a 'time series of the kimchi premium from the continuous archive' ordered 'newest-last', which is specific about the resource and output kind. It implies historical data retrieval but does not explicitly contrast with sibling tools like kimchi_premium or kimchi_premium_stats.
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 context is implied through phrases like 'continuous archive' and 'time series', so an agent can infer this tool is for historical premium data. However, the description does not explicitly state when to prefer this over kimchi_premium or kimchi_premium_stats, nor does it provide exclusions.
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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