Context Injection

# Context Injection

Automatically inject relevant context the agent didn't request.

## Category
Tool Context

## Context
Tools where additional context improves results.

## Problem
Agents may not know to request context they'll need.

## Solution
Inject context automatically:
- **User context**: Current user's team, permissions
- **Temporal context**: Current time, timezone
- **Environmental**: Region, feature flags
- **Relational**: Related entities

## Example (Python)
```python
@tool
def search_tasks(
    query: str,
    # Context auto-injected, can be overridden
    team_id: str | None = None,
    include_completed: bool = False
) -> TaskList:
    """Search tasks. Defaults to current user's team.
    
    Context is automatically injected:
    - team_id: Current user's team (from session)
    - timezone: For date interpretation
    """
    tid = team_id or session.get("team_id")
    tz = session.get("timezone", "UTC")
    
    results = tasks_api.search(query, team_id=tid, tz=tz)
    return TaskList(
        tasks=results,
        context=SearchContext(team_id=tid, timezone=tz)
    )
```

## Considerations
- Expand machine identifiers with human-friendly names/representations when possible
- Document what context is injected
- Allow explicit overrides
- Include injected context in the response

## Related Patterns
- identity-anchor
- context-boundary
- smart-defaults

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