Fix DISABLE_TOOLS array parsing error

[DanielSinclair]

Problem

The current implementation expects DISABLE_TOOLS to be an array directly in the Zod schema:

DISABLE_TOOLS: z
  .array(z.string())
  .default(['delete-item'])

However, environment variables are always strings. When users set:

export DISABLE_TOOLS='["delete-item", "update-field"]'

The configuration parsing would fail because the string couldn't be converted to an array.

Solution

Updated the configuration schema to accept a JSON string and parse it into an array:

DISABLE_TOOLS: z
  .string()
  .default('["delete-item"]')
  .transform((val) => JSON.parse(val))
  .pipe(z.array(z.string()))

Changes Made

1. src/config.ts: Modified DISABLE_TOOLS schema to parse JSON strings
2. README.md: Updated example configuration to show proper JSON string format:

   - "DISABLE_TOOLS": ["delete-item", "update-field"],
   + "DISABLE_TOOLS": "[\"delete-item\", \"update-field\"]",

Real-world Usage

Users can now properly set this in their environment:

# Shell
export DISABLE_TOOLS='["delete-item", "update-field", "read-users"]'

# .env file
DISABLE_TOOLS=["delete-item", "update-field"]

{
  "mcpServers": {
    "directus": {
      "command": "npx",
      "args": ["@directus/content-mcp@latest"],
      "env": {
        "DIRECTUS_URL": "https://your-directus-instance.com",
        "DIRECTUS_TOKEN": "your_directus_token",
        "DISABLE_TOOLS": "[\"delete-item\", \"update-field\"]"
      }
    }
  }
}