# ToolFit by YourAITools – Full AI Agent Tool Schema Audit

> ToolFit by YourAITools – Full AI Agent Tool Schema Audit is a paid API for AI agents from api.youraitools.co, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-25).

Performs a comprehensive schema audit of an agent's tool list or remote MCP server, returning per-provider issues, rewritten definitions, confusable tool pairs, poisoning lints, and fingerprints.

## Facts

- Endpoint: GET https://api.youraitools.co/toolfit/v1/full?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-25
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/toolfit-by-youraitools-full-ai-agent-tool-schema-audit-04d77c56
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_EN5eqQtX84Hpq5R11GmLc

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability toolfit-by-youraitools-full-ai-agent-tool-schema-audit-04d77c56
```

Example prompt: Can you run a full schema audit on my tool list against OpenAI, Anthropic, and Gemini — I need to see every error with the JSON path, get rewritten definitions that pass each provider, and flag any tools that look confusable or have poisoning risks?

## When to prefer this

Choose this endpoint when you need a single comprehensive audit covering all major LLM providers (OpenAI including strict mode, Anthropic, Gemini, Bedrock, MCP) at once, rather than provider-specific validators. It is especially valuable when you need rewritten definitions ready to use, poisoning/injection detection, confusable tool diagnosis, and a stable fingerprint pin for tracking tool set changes over time — capabilities not available in generic JSON Schema validators.

## Known failure modes

- Invalid or unreachable MCP URL returns an error indicating the server could not be fetched
- Tool array exceeding 500 entries is rejected
- Missing required 'type' or 'method' fields in input causes a 400 validation error
- Unsupported provider enum value returns a validation error
- Payment failure (x402) blocks the request before processing
- Malformed tool JSON in the tools array may cause partial or failed analysis

## How this service works

Full AI agent tool schema audit API (MCP and function calling). Full audit of an agent tool list (tools array or public remote MCP URL): every schema issue per provider (OpenAI, Anthropic, Gemini, Bedrock, MCP; strict mode opt-in) with JSON path and source link, rewritten definitions per provider, confusable tool pairs with distinguishing terms and fix hints, description and poisoning lints, per-tool fingerprints and a pin.

## Output

Returns a JSON object with: an overall compatibility grade (e.g. 'D') and numeric score, total tool count, an array of issues each with tool name, provider, rule, severity, and JSON path, per-provider compatibility flags and error counts, rewritten (fixed) tool definitions per provider with change counts, confusable tool pairs with high-risk count and distinguishing hints, poisoning findings with severity counts, token usage stats (avg and total), and a fingerprint pin (set_id) for the audited tool set.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [],
     "properties": {
      "url": {
       "type": "string",
       "description": "Public remote MCP server URL (Streamable HTTP, https), e.g. https://api.youraitools.co/mcp/hub. ToolFit only lists its tools."
      },
      "tools": {
       "type": "array",
       "items": {
        "type": "object"
       },
       "description": "Tool definitions: MCP tools/list entries, OpenAI {type:\"function\",function:{...}}, Anthropic {name,description,input_schema}, Gemini functionDeclarations or Bedrock toolSpec. Max 500."
      },
      "providers": {
       "type": "array",
       "items": {
        "enum": [
         "openai",
         "openai_strict",
         "anthropic",
         "gemini",
         "bedrock",
         "mcp"
        ],
        "type": "string"
       },
       "description": "Providers to check (default openai, anthropic, gemini, bedrock, mcp; add openai_strict for Structured Outputs strict mode). GET: comma list."
      }
     },
     "description": "Search intents: tool schema audit, mcp tool rewrite, function calling fix, gemini schema compatibility, tool poisoning check, agent tools quality"
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "pin": {
       "type": "object"
      },
      "fixed": {
       "type": "object"
      },
      "grade": {
       "type": "string"
      },
      "score": {
       "type": "number"
      },
      "tools": {
       "type": "number"
      },
      "issues": {
       "type": "array"
      },
      "tokens": {
       "type": "object"
      },
      "poisoning": {
       "type": "object"
      },
      "providers": {
       "type": "object"
      },
      "confusable": {
       "type": "object"
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "pin": {
   "set_id": "ts_0123456789abcdef0123456789abcdef"
  },
  "fixed": {
   "openai": {
    "changed": 8
   }
  },
  "grade": "D",
  "score": 62,
  "tools": 31,
  "issues": [
   {
    "path": "description",
    "rule": "description_length",
    "tool": "read_url",
    "provider": "openai",
    "severity": "error"
   }
  ],
  "tokens": {
   "avg": 374,
   "total": 11585
  },
  "poisoning": {
   "high": 0,
   "findings": 0
  },
  "providers": {
   "gemini": {
    "errors": 9,
    "compatible": false
   },
   "openai": {
    "errors": 8,
    "compatible": false
   },
   "anthropic": {
    "errors": 0,
    "compatible": true
   }
  },
  "confusable": {
   "high": 1,
   "count": 5
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/toolfit-by-youraitools-full-ai-agent-tool-schema-audit-04d77c56/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.youraitools.co](https://www.zero.xyz/host/api.youraitools.co/llms.txt)