Context Boundary

# Context Boundary

Define the scope or boundaries of tool operations.

## Category
Tool Context

## Context
Tools that operate on file systems, databases, or multi-tenant systems.

## Problem
Tools need clear boundaries on what they can access or modify.

## Solution
Define context boundaries:
- **Root paths**: What directories are accessible
- **Tenant scope**: What data tenant to use
- **Permission scope**: What operations are allowed
- **Resource limits**: Quotas and limits

## Example (Python)
```python
@tool
def list_files(
    path: str = "."
) -> FileList:
    """List files in the allowed workspace.
    
    Boundary: Only files within /workspace are accessible.
    Attempting to access parent directories will fail.
    """
    root = context.get_root()  # e.g., /workspace
    full_path = os.path.join(root, path)
    
    # Enforce boundary
    if not full_path.startswith(root):
        raise PermissionError("Access outside workspace not allowed")
    
    return FileList(files=os.listdir(full_path))
```

## Considerations
- Define boundaries explicitly at tool initialization
- Validate all paths against boundaries
- Return clear errors when boundaries are violated

## Related Patterns
- permission-gate
- identity-anchor
- secret-injection

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Source: https://arcade.dev/patterns/context-boundary