Summary

Fixes #90

Every ToolManager instance automatically copies the global tool registry (_GLOBAL_TOOL_REGISTRY), so all agents receive move_one_step, teleport_to_location, and speak_to regardless of whether those capabilities make sense for the agent. This causes:

• Capability leakage — static entities gain movement tools
• Tool noise — LLMs waste reasoning on irrelevant tools
• Hard-to-debug conflicts — custom tools can shadow built-ins
• No local permission reasoning — cannot restrict agent capabilities

Changes

tool_manager.py:

• Add include_builtins parameter to ToolManager.__init__() (default True for full backward compatibility)
• When False, the manager starts with an empty tool set — only extra_tools (if provided) are registered
• Add remove_tool(name) method for fine-grained per-instance tool removal

llm_agent.py:

• Add include_builtin_tools parameter to LLMAgent.__init__() that passes through to ToolManager

Tests (5 new):

• test_include_builtins_false_starts_empty — verifies no global tools when disabled
• test_include_builtins_true_includes_global_tools — verifies default behavior preserved
• test_include_builtins_false_with_extra_tools — verifies only extras are available
• test_remove_tool — verifies removal works
• test_remove_tool_missing_is_silent — verifies no error on missing tool

Usage Example

# Agent WITHOUT spatial tools (e.g., dining philosopher)
class Philosopher(LLMAgent):
    def __init__(self, model, **kwargs):
        super().__init__(model, include_builtin_tools=False, **kwargs)
        # Only register tools relevant to this agent
        self.tool_manager.register(pick_up_fork)
        self.tool_manager.register(put_down_fork)

# Agent WITH default tools (backward compatible, no change needed)
class Explorer(LLMAgent):
    def __init__(self, model, **kwargs):
        super().__init__(model, **kwargs)  # gets all built-ins

Test Plan

• All 267 existing tests pass (5 new)
• Pre-commit hooks pass (ruff, codespell)
• Fully backward compatible (default include_builtins=True)