# Tool Poisoning Attack Prevention

## What is Tool Poisoning?

Tool Poisoning is a significant security threat in systems that utilize external or dynamically loaded tools, particularly in AI and Large Language Model (LLM) ecosystems. It occurs when a malicious actor successfully deploys a tool that masquerades as a legitimate, trusted tool. The aim is to deceive users, or the LLM itself, into executing the malicious tool, leading to various harmful outcomes.

### Attack Vectors

1.  **Identity Spoofing**: The malicious tool uses a name, description, or provider information identical or very similar to a known trusted tool.
2.  **Deceptive Functionality**: The tool might appear to perform its advertised function correctly for simple cases, while secretly carrying out malicious activities in the background or for specific inputs.
3.  **Lack of Verification**: Systems that don't rigorously verify tool authenticity, origin, or integrity are vulnerable.

### Potential Impacts

-   **Data Theft**: Exfiltration of sensitive information, PII, credentials, or proprietary data processed by the tool.
-   **Malware Execution**: Running arbitrary code on the host system or within the user's environment.
-   **Privilege Escalation**: Gaining unauthorized access or higher privileges within the system.
-   **Denial of Service (DoS)**: Disrupting the availability of the system or legitimate tools.
-   **Compromise of LLM Integrity**: Manipulating LLM outputs, behavior, or decision-making processes.
-   **Supply Chain Attacks**: If the poisoned tool is itself a development or integration tool, it can compromise a wider ecosystem.

## ETDI's Mitigation Strategies

The Enhanced Tool Definition Interface (ETDI) provides a robust framework to combat tool poisoning attacks through multiple layers of security:

1.  **Cryptographic Signatures & Verification**:
    *   **Authenticity**: Tools are cryptographically signed by their providers. ETDI clients verify these signatures, typically by having access to the provider's public key or by retrieving it from a trusted source, before execution.
    *   **Integrity**: The signature ensures that the tool's definition and metadata have not been tampered with since publication.

2.  **Provider Authentication & Trust Management**:
    *   **OAuth 2.0 Integration**: ETDI encourages tools to be protected by OAuth 2.0, ensuring that the tool provider is authenticated. This helps confirm the identity of the entity serving the tool.
    *   **Client-Side Verification**: The ETDI client is responsible for verifying the authenticity of the tool provider, often through mechanisms like checking the issuer of an OAuth token or validating a known signature.

3.  **Rich Security Metadata**:
    *   ETDI tool definitions include comprehensive security metadata, such as required permissions (scopes), call stack constraints, and data handling policies.
    *   Clients can analyze this metadata *before* tool execution to assess risk and enforce policies.

4.  **Client-Side Security Analysis Engine**:
    *   ETDI clients incorporate a security analysis engine that evaluates tools based on their ETDI compliance, signature validity, OAuth protection, and other security attributes.
    *   This engine can assign trust scores and make informed decisions (allow, warn, block) about tool execution.

5.  **Secure Tool Discovery & Invocation Workflow**:
    *   **Discovery**: Clients prioritize tools with strong ETDI security signals.
    *   **Verification**: Mandatory verification steps before a tool is considered for execution.
    *   **Approval (Optional)**: For sensitive operations or less trusted tools, user or administrative approval can be enforced.

## Best Practices for Developers and Users

*   **Providers**: Always sign your tools with a strong private key. Protect your tools with OAuth 2.0. Clearly define security metadata.
*   **Developers (integrating ETDI)**: Implement rigorous signature verification. Use the ETDI client's security analysis capabilities. Prefer tools with complete and verified ETDI metadata.
*   **Users**: Be cautious of tools from unverified sources. Pay attention to warnings from ETDI-compliant clients.

By combining these technical measures and best practices, ETDI significantly raises the bar against tool poisoning attacks, fostering a more secure and trustworthy tool ecosystem.

## Related Documentation

- [Overall Attack Prevention Strategies](../attack-prevention.md)
- [Rug Poisoning Protection](./rug-poisoning.md)
- [Security Features Overview](../security-features.md)
- [Tool Poisoning Demo Example](../examples/etdi/tool_poisoning_demo.md)
- [Integration Guide](../../integration-guide.md)
- [FastMCP Security](../fastmcp/index.md) 