agent-disallowed-tools

Agent disallowedTools must be an array of tool names

Error

Rule Details

This rule enforces that the disallowedTools field in agent markdown frontmatter is a valid array of strings. Each entry should be a tool name that the agent is prohibited from using. Validation is delegated to the AgentFrontmatterSchema Zod schema. Proper formatting prevents runtime errors when the agent framework parses tool restrictions.

Incorrect

disallowedTools as a single string instead of array

---
name: safe-agent
description: Agent with tool restrictions
disallowedTools: Bash
---

disallowedTools with non-string entries

---
name: safe-agent
description: Agent with tool restrictions
disallowedTools:
  - 123
  - true
---

Correct

disallowedTools as a valid array of tool names

---
name: safe-agent
description: Agent with tool restrictions
disallowedTools:
  - Bash
  - Write
---

How To Fix

Ensure disallowedTools is formatted as a YAML array of strings. Each entry should be a valid tool name like Bash, Write, Edit, or WebFetch.

Options

This rule does not have any configuration options.

Related Rules

• agent-tools

Resources

• Rule Implementation
• Rule Tests

Version

Available since: v0.2.0