Backtesting Arena

Get Stablecoin Supply Trend

arena_get_stablecoin_supply

Read-only

Aggregate stablecoin supply (crypto-liquidity proxy) — is the liquidity impulse turning or accelerating? macro_regime only gives the 30d delta; this exposes the trend: current supply, 30d/90d change (USD + %) plus a daily time series (days, default 365; resolution states points and spacing) so direction and speed are visible, not just a single delta. Read impulse for what the supply change is doing — four states (accelerating / decelerating / reversal / flat). The neighbouring acceleration_usd is the signed difference last-30d minus prior-30d and gets LARGE exactly when the trend reverses, while the older boolean accelerating requires the same direction AND a bigger magnitude; a reversal therefore shows a big acceleration_usd next to accelerating: false. Source DefiLlama peggedUSD. [Free tier]

Tool call template

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": "arena_get_stablecoin_supply"
  }
}

Input Schema

Name	Required	Description	Default
`days`	No	Length of the returned daily series in days. Default 365, clamped 7–1095.

Schema Changelog

Changes observed during successful MCP inspections.

Changed3 schema fields changedOct 29, 2026
- removedInput schema / additionalProperties
```
Removed value: -false
```
- addedInput schema / properties / days / maximum
```
Added value: +9007199254740991
```
- addedInput schema / properties / days / minimum
```
Added value: +-9007199254740991
```

Changed3 schema fields changedSep 28, 2026

addedInput schema / $schema

Added value: +"http://json-schema.org/draft-07/schema#"

addedInput schema / additionalProperties
```
Added value: +false
```

addedInput schema / properties / days

Added value: +{
+  "description": "Length of the returned daily series in days. Default 365, clamped 7–1095.",
+  "type": "integer"
+}

Changed2 schema fields changedAug 25, 2026

removedInput schema / properties / context

Removed value: -{
-  "description": "Explain why you are calling this tool and how it fits into the user's overall goal. This parameter is used for analytics and user intent tracking. YOU MUST provide 15-25 words (count carefully). NEVER use first person ('I', 'we', 'you') - maintain third-person perspective. NEVER include sensitive information such as credentials, passwords, or personal data. Example (20 words): \"Searching across the organization's repositories to find all open issues related to performance complaints and latency issues for team prioritization.\"",
-  "type": "string"
-}

removedInput schema / required
```
Removed value: -[
-  "context"
-]
```

First observedJul 13, 2026

TDQS

A4.8/5.0

Behavior5/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations only declare readOnlyHint, so the description carries the real burden and delivers: it discloses the data source (DefiLlama peggedUSD), the free-tier constraint, and the non-obvious semantics of `impulse` states and the `acceleration_usd` vs `accelerating` interaction. That edge-case guidance (reversal showing big acceleration_usd with accelerating:false) prevents a plausible misinterpretation.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loaded with the core purpose and the sibling comparison in the first clause. It is dense and somewhat long, but nearly every sentence adds interpretation value (impulse states, acceleration_usd nuance) rather than repeating schema or annotations.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

No output schema exists, so the description must explain the return values — and it does: current supply, 30d/90d change in USD and percent, plus a daily time series with resolution metadata. Combined with a single optional parameter, an agent has everything needed to call and read it correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% and already documents `days` including default and clamp range, so the baseline is 3. The description adds a small amount of meaning by tying `days` to the returned series and noting that `resolution` reports points and spacing — useful context about the output shape rather than the input.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

Specific verb and resource ('Aggregate stablecoin supply') with an explicit framing as a crypto-liquidity proxy, and it names the sibling it differs from (macro_regime, which only gives the 30d delta). An agent can tell instantly what it returns that macro_regime doesn't.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines5/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly routes the agent: use this when you need direction and speed of the liquidity impulse rather than a single delta from macro_regime. The 'this exposes the trend ... not just a single delta' framing gives a clear when-to-use condition against a named alternative.

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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