Populate required array in MCP custom tool inputSchema

[Copilot]

Why make this change?

• The JSON Schema inputSchema of MCP custom tools omitted the required array, so consumers could not tell which stored procedure parameters were mandatory. Expected required: ["firstName", "lastName"]; actual was unpopulated.

What is this change?

• DynamicCustomTool now emits a required array in both schema-building paths, treating a parameter as required when it has no default value to fall back on — consistent with the existing OpenApiDocumentor convention.
  • BuildInputSchemaFromDbMetadata: requires params where !HasConfigDefault.
  • BuildInputSchemaFromConfig: requires params where Default is null.
  • The required key is only added when at least one parameter qualifies, keeping schemas clean for zero-param / fully-defaulted procedures.

{
  "type": "object",
  "properties": {
    "firstName": { "type": "string", "description": "Parameter firstName" },
    "lastName":  { "type": "string", "description": "Parameter lastName" },
    "nickname":  { "type": "string", "description": "Parameter nickname (default: guest)" }
  },
  "required": ["firstName", "lastName"]
}

How was this tested?

• Integration Tests
• Unit Tests

Added coverage in DynamicCustomToolTests for both the config-based and DB-metadata-based paths, verifying non-defaulted params are listed in required and defaulted ones are excluded.

Sample Request(s)

MCP tools/list returns the custom tool with a populated required array:

{
  "name": "get_user",
  "inputSchema": {
    "type": "object",
    "properties": { "firstName": { "type": "string" }, "lastName": { "type": "string" } },
    "required": ["firstName", "lastName"]
  }
}