tool_filter

Filter tool definitions using Hasura-style matching rules.

Evaluates each tool definition in the request against a Hasura-style filter. Tool definitions are normalized to a flat shape before filtering: {"name": "...", "description": "...", "parameters": {...}, "type": "..."} This works identically for OpenAI and Anthropic tool formats.

Supports three actions: block (reject request), strip (remove matching tools), or log (audit only).

Configuration

Field	Type	Default	Description
filter	object	Required	Hasura-style filter applied to each normalized tool definition.
scope	string	"any"	'any': trigger if any tool matches. 'every': trigger if all tools match. 'none': trigger if no tools match (useful for requiring a tool).
action	string	"block"	'block': reject the request. 'strip': remove matching tools from the request. 'log': log the finding without blocking.

Examples

# Block tools with suspicious descriptions
type: tool_filter
config:
  filter:
    description:
      _iregex: ignore previous|disregard|system prompt
  action: block

# Strip shell execution tools
type: tool_filter
config:
  filter:
    name:
      _ilike: '%execute%'
  action: strip