SYNTHORA top-crypto: Top N cryptocurrencies by market cap (default 10, max 50): rank, price, 24h change, volume and market cap in USD. Source: CoinGecko free API, keyless, timestamped. [x402: 0.01 USDC per call on Base]
| Name | Required | Description | Default |
|---|---|---|---|
| limit | No | top N, default 10, max 50 |
Changes observed during successful MCP inspections.
Input schema / examplesAdded value: +[
+ {
+ "limit": 10
+ }
+]Input schema / properties / inputRemoved value: -{
- "description": "product parameters (JSON or text). Example: {\"limit\": 10}",
- "type": "string"
-}Input schema / properties / limitAdded value: +{
+ "description": "top N, default 10, max 50",
+ "examples": [
+ 10
+ ],
+ "type": "integer"
+}Input schema / properties / input / descriptionPrevious value: -"product parameters (JSON or text). Example: {\"input\": \"{\\\"limit\\\": 10}\"}"New value: +"product parameters (JSON or text). Example: {\"limit\": 10}"Input schema / properties / input / descriptionPrevious value: -"product parameters (JSON or text). Example: {\"limit\": 10}"New value: +"product parameters (JSON or text). Example: {\"input\": \"{\\\"limit\\\": 10}\"}"Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly/openWorld/idempotent/non-destructive, so the safety profile is covered. The description adds genuinely useful behavioral context beyond that: the data source (CoinGecko free API), that it is keyless, that results are timestamped, and critically that each call costs 0.01 USDC via x402 on Base. It does not cover rate limits or failure modes.
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?
One dense, front-loaded sentence delivers the resource, the default/max bounds, the returned fields, the data source, and the payment requirement with no filler. Every clause earns its place.
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, one-parameter ranking tool with no output schema, the description compensates by enumerating the returned fields and adding source, freshness ('timestamped'), and cost information. An agent has everything needed to decide and call 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?
There is a single optional 'limit' parameter with 100% schema description coverage, and the description merely restates the schema's 'default 10, max 50'. Baseline 3 is appropriate since the schema already carries the parameter semantics.
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 gives a precise verb+resource ('Top N cryptocurrencies by market cap') and enumerates the returned fields (rank, price, 24h change, volume, market cap in USD), which makes it easy to distinguish from stablecoin_supply or defi_llama_tvl_ranking. It stops short of explicitly naming or contrasting any sibling, so it lands just below the top mark.
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 implied rather than stated: an agent can infer this is the tool for a general crypto market-cap leaderboard, and the default/max limit is given. There is no explicit when-to-use, when-not-to-use, or alternative-tool guidance for the crypto-adjacent siblings.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.