Dependency Hint

# Dependency Hint

Embed 'call X before Y' guidance in tool descriptions.

## Category
Tool Discovery

## Context
Tools that depend on data from other tools.

## Problem
Agents don't know the prerequisite tools for a given operation.

## Solution
Include dependency hints:
- **Prerequisites**: "If you don't have X, call Y first"
- **Follow-ups**: "After this, you might want Z"
- **Alternatives**: "If this fails, try W"

## Example (Python)
```python
@tool
def update_user(user_id: str, **fields) -> User:
    """Update a user's profile.
    
    Args:
        user_id: The user's ID. If you only have an email
                or name, call search_users() first.
    
    Prerequisite: search_users() to find user_id
    Follow-up: get_user() to verify changes
    """
```

## Considerations
- Be specific about what data is needed
- Include the prerequisite tool name explicitly
- Consider returning hints in error messages too

## Related Patterns
- tool-description
- recovery-guide

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Source: https://arcade.dev/patterns/dependency-hint