# MCP Tool Definition Normalizer

> MCP Tool Definition Normalizer is a paid API for AI agents from agent.halowerk.com, paid per call via x402, $0.002/call, status unknown (last checked 2026-09-13).

Accepts a list of MCP tool definitions from one or more servers and rewrites them into a single, consistent schema form, resolving variations in field names like inputSchema, input_schema, parameters, schema, and arguments.

## Facts

- Endpoint: POST https://agent.halowerk.com/v1/mcp-normalize
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/mcp-tool-definition-normalizer-1dc7c430
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_SuzuxOUwSZ5sTBnseG60R

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 mcp-tool-definition-normalizer-1dc7c430 -d '<json body>'
```

Example prompt: I just fetched tool definitions from three different MCP servers and they all use different field names — some use inputSchema, others use parameters or arguments. Can you normalize all of them into one consistent shape so I can process them uniformly?

## When to prefer this

Choose this endpoint when your agent consumes MCP tool definitions from multiple servers that use inconsistent field naming conventions and you need a single canonical representation before further processing, routing, or indexing. It is the right choice when silent field loss from schema name mismatches is a concern and when you need to know exactly which variant each server used.

## Known failure modes

- Input list is empty — returns an error or empty result
- Tool definition lacks any recognized schema field — tool may be returned without a schema or flagged
- Malformed JSON in tool definitions — parse error returned
- Unrecognized schema field variant not in the known set — silently passed through or flagged

## How this service works

Takes a list of MCP tool definitions, as returned by tools/list on any number of servers, and rewrites them into one common form. Servers disagree on where the schema lives — inputSchema, input_schema, parameters, schema or arguments are all in use — and a consumer reading only one of them loses the others silently; every spelling is accepted and the one found is reported.

## Output

A list of rewritten MCP tool definitions in a single canonical schema form, with each tool's schema field unified to one consistent name regardless of the original spelling (inputSchema, input_schema, parameters, schema, or arguments). The response also reports which field name variant was found for each tool.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "tools": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "name"
    ],
    "properties": {
     "name": {
      "type": "string",
      "minLength": 1,
      "description": "Tool name."
     },
     "server": {
      "type": "string",
      "description": "Which server the tool came from. Used for collision reporting."
     }
    }
   },
   "maxItems": 200,
   "minItems": 1,
   "description": "The MCP tool definitions to normalise."
  },
  "naming": {
   "enum": [
    "snake_case",
    "preserve"
   ],
   "type": "string",
   "default": "snake_case",
   "description": "How to normalise tool names."
  },
  "include_examples": {
   "type": "boolean",
   "default": true,
   "description": "Build a synthetic example call per tool."
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/mcp-tool-definition-normalizer-1dc7c430/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent.halowerk.com](https://www.zero.xyz/host/agent.halowerk.com/llms.txt)