Audit one MCP toolset for the defects that stop an agent calling it correctly
Audit one MCP toolset for the defects that stop an agent calling it correctly: a missing or non-object inputSchema, an argument with no type or no description, a required argument the schema never declares, a duplicated tool name, contradictory annotation hints, and a tool whose name reads as state-changing while declaring no hints at all.
Answeringour last check, 2026-10-04
1 of 1checks answered this week
3372 msmedian answer time
$0.1listed price per call
$0.1price it asked us
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
POST https://api.zfinia.com/x402/v1/mcp-tool-schema-audit
| Category | Code and developer |
|---|---|
| Provider host | api.zfinia.com |
| Networks | eip155:8453 |
| Payment schemes | exact |
| Self-reported calls, 30 days | 1 from 1 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-10-04 | valid payment request | 402 | $0.1 | 3372 ms |
Example input (from the provider)
{
"body": {
"toolset": {
"tools": [
{
"inputSchema": {
"properties": {
"q": {}
},
"type": "object"
},
"name": "search"
},
{
"description": "Remove all records.",
"inputSchema": {
"properties": {
"confirm": {
"type": "boolean"
}
},
"required": [
"confirm",
"scope"
],
"type": "object"
},
"name": "purgeEverything"
},
{
"annotations": {
"destructiveHint": true,
"readOnlyHint": true
},
"description": "Read a file from disk and return its contents as text.",
"inputSchema": {
"type": "array"
},
"name": "read_file"
}
]
}
},
"bodyType": "json",
"method": "POST",
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"additionalProperties": false,
"properties": {
"require_descriptions": {
"type": "boolean"
},
"require_output_schemas": {
"type": "boolean"
},
"toolset": {}
},
"required": [
"toolset"
],
"type": "object"
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
},
"method": {
"enum": [
"POST"
],
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method",
"bodyType",
"body"
],
"type": "object"
},
"output": {
"properties": {
"example": {
"type": "object"
},
"type": {
"type": "string"
}
},
"required": [
"type"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}