ExchangeRebel — pay-per-call APIs for AI agents (x402 on Solana)

true_cost_precheck

FREE headline pre-check (100/day per wallet; pass caller). Returns assessability only - whether the quote request is complete for the published fee model; no fee figures are returned.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "caller": "<caller>",
      "quote": "<quote>"
    },
    "name": "true_cost_precheck"
  }
}

Input Schema

Name	Required	Description	Default
`quote`	Yes	The quote request: seller_price_micro, facilitator, scheme, and the facilitator's position inputs where its fee model needs them (e.g. cdp_monthly_tx_position for CDP past the free tier).
`caller`	Yes	Solana base58 wallet of the operator; keys the free allowance (100/day per wallet).

Schema Changelog

Changes observed during successful MCP inspections.

AddedNov 3, 2026

TDQS

A3.7/5.0

Behavior4/5

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

With no annotations, the description carries the load and does well: it discloses the quota (100/day per wallet, keyed by caller), that the tool is free, and precisely what is returned ('assessability only', no fee figures). What's missing is failure behavior when the quota is exhausted or when the quote is incomplete on the response side.

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?

Two sentences, front-loaded with the free/precheck framing then the return contract. The parenthetical quota note is dense but compact; little if anything is wasted.

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

Completeness4/5

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 correctly spells out the return semantics (assessability only, no fee figures) and the quota ceiling. For a two-parameter precheck this is nearly complete; only quota-exhaustion or invalid-quote behavior is left implicit.

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

Parameters3/5

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

Schema description coverage is 100%, so both parameters (caller, quote) are already documented in the schema, including the nested quote fields and the free-tier note. The description only adds 'pass caller' for the allowance linkage, which is near-zero marginal meaning.

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

Purpose4/5

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

States a specific verb and resource: a 'FREE headline pre-check' that returns 'assessability only - whether the quote request is complete for the published fee model'. The negative clause 'no fee figures are returned' implicitly distinguishes it from the true_cost_quote sibling, though it never names that sibling by name.

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

Usage Guidelines3/5

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

The 'pre-check' framing and 'pass caller' instruction imply this runs before obtaining a quote, and the 'FREE'/'100/day per wallet' detail tells the agent the cost of invoking it. However, no explicit when-to-use vs. true_cost_quote or true_cost_criteria routing is given, so the agent must infer the ordering.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

All ExchangeRebel — pay-per-call APIs for AI agents (x402 on Solana) tools Inspect

Try in Browser

Claude Code, inside the Godot 4 editorFlockbay puts an AI agent in the real Godot 4 editor: it writes GDScript, runs your game and fixes what breaks. Free, or bring your own Claude Code or Codex.flockbay.comAd

Glama MCP Gateway

Add one secure layer between your agents and this server.

Resources

Need Help?