# Tool Filter

> Use this tool when you need to restrict access to specific tools from upstream MCP servers, filter out unwanted tools using regex-based patterns, and expose only allowed tools through a standard MCP interface. It solves problems of fine-grained control and security by applying configurable deny patterns to tool access. Ideal for organizations requiring selective tool exposure while maintaining MCP compatibility and performance.

Canonical page: https://skillsregistry.net/skills/respawn-app-tool-filter  
JSON: https://api.skillsregistry.net/v1/skills/respawn-app-tool-filter

## Description

Tool Filter MCP provides a proxy server that filters tools from upstream MCP servers using regex-based deny patterns, enabling fine-grained control over which tools are exposed. Built by Respawn App using TypeScript and the official Anthropic MCP SDK, it connects to upstream MCP servers via SSE transport, applies configurable regex patterns to filter out unwanted tools, and exposes only the allowed tools through a standard MCP interface. The implementation includes robust regex validation with ReDoS protection, error handling, timeout management, and maintains tool caching for performance, making it valuable for organizations that need to restrict access to specific subsets of available tools while maintaining full MCP compatibility and transparent proxying of allowed tool calls.

## Trust

- **Trust score (0–1):** 0.95
- **Verification tier:** verified
- **Last scanned:** 2026-09-28

## Facts

- **Version:** 1.0.0
- **Skill type:** atomic
- **Execution layer:** mcp-remote
- **Runtime environment:** api
- **Category:** ai-ml
- **Updated:** 2026-09-28

## Source

- **Source listing:** [PulseMCP](https://www.pulsemcp.com/servers/respawn-app-tool-filter)
- **Repository:** <https://github.com/respawn-app/tool-filter-mcp>

## Use it

Resolve this record through the SkillsRegistry MCP server (no auth, read-only):

```
claude mcp add --transport http --scope user skillsregistry https://api.skillsregistry.net/mcp
```

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "get_skill",
    "arguments": {
      "slug": "respawn-app-tool-filter"
    }
  }
}
```

REST: `GET https://api.skillsregistry.net/v1/skills/respawn-app-tool-filter` · pull for local use: `GET https://api.skillsregistry.net/v1/skills/respawn-app-tool-filter/pull`

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SkillsRegistry indexes agent skills from public registries and GitHub. Skills we have analysed are scanned with Circle-IR and scored on six dimensions; each listing states its scan coverage. More: https://skillsregistry.net/llms.txt