AgentWallet MCP Server

discover_x402

Search the public x402 index by keyword to find paid APIs with method, price, and chain re-priced from this client's registry. Use results to pick an API before requesting a quote or payment.

Instructions

Find x402-paid APIs by subject in the public x402 index (the Bazaar published by the CDP facilitator). Returns resources with their method, price and chain, re-priced from this client's own registry. Listings are sellers' own words. Nothing is paid; follow up with quote_x402 or pay_x402.

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": "discover_x402"
  }
}

Input Schema

Name	Required	Description
`limit`	No	How many matches to return
`query`	No	Words that must all appear in the resource URL, service name, description or tags (case-insensitive)
`offset`	No	Index offset to continue from (use next_offset from the previous call)
`chain_id`	No	Only resources payable on this chain

Schema Changelog

Changes observed during successful MCP inspections.

Changed2 schema fields changedv1.14.8Oct 27, 2026
- addedInput schema / properties / chain_id / maximum
```
Added value: +9007199254740991
```
- addedInput schema / properties / chain_id / minimum
```
Added value: +-9007199254740991
```
Addedv1.14.2Oct 14, 2026

TDQS

A4.2/5.0

Behavior4/5

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

With no annotations, the description carries the full burden and does well: it names the public index source, explains that results are re-priced from this client's registry, warns that listings are sellers' own words, and clarifies that no payment occurs. It omits details such as rate limits or authentication requirements, keeping it short of fully exhaustive.

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

Conciseness5/5

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

The description is front-loaded with the core action and source, then adds concise return and safety context. Every sentence contributes useful information without repetition.

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?

There is no output schema, so the description usefully explains that results include method, price, and chain, and notes re-pricing and seller-authored listings. It stops short of describing pagination or full result structure, but is sufficient for an agent to understand the tool's role.

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 coverage is 100%, so all four parameters are already documented. The description adds only the phrase 'by subject', which loosely maps to the query parameter but does not provide additional syntax, filtering behavior, or pagination guidance beyond the schema.

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?

The description uses a specific verb-resource pair: 'Find x402-paid APIs by subject in the public x402 index'. It also identifies the data source (Bazaar/CDP facilitator) and distinguishes this discovery step from the follow-up quote_x402 and pay_x402 tools.

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

Usage Guidelines4/5

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

It clearly frames discovery as the step before quote_x402 or pay_x402 and explicitly states 'Nothing is paid', which prevents misuse as a payment tool. It does not spell out exclusions or when to prefer another discovery path, but the intended context is clear.

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