Append tool usage instructions to system prompt when creating LLM instances

[Copilot]

The Tool.usage_instructions_to_llm field was being ignored when initializing LLM instances, preventing tools from providing usage guidance to the model.

Changes

• Modified _create_llm() in MicroBot.py: Concatenate all tool usage instructions to the system prompt before passing to LLM constructors (OpenAI, Anthropic, OllamaLocal)
• Added unit tests: Verify single/multiple tool instructions are appended correctly and system prompt remains unchanged when no tools provided

Example

tool = Tool(
    name="cscope",
    usage_instructions_to_llm="# Non-interactive cscope usage\ncscope -L <query_type> <symbol>",
    # ... other fields
)

bot = MicroBot(
    model="anthropic/claude-sonnet-4",
    system_prompt="You are a helpful assistant.",
    additional_tools=[tool]
)

# bot.llm.system_prompt now contains:
# "You are a helpful assistant.\n\n# Non-interactive cscope usage\ncscope -L <query_type> <symbol>"

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Append tool usage instructions in system prompt before creating LLM messages</issue_title>
<issue_description>Tool usage instructions are not considered while passing system prompt to LLM.</issue_description>

<agent_instructions>Class Tool in tool.py is getting an argument as usage_instructions_to_llm from the client application. That value should be appended to the system prompt before the system prompt in the _create_llm function. Check this and fix it.</agent_instructions>

Comments on the Issue (you are @copilot in this section)

• Fixes Append tool usage instructions in system prompt before creating LLM messages #87

---

💬 We'd love your input! Share your thoughts on Copilot coding agent in our 2 minute survey.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 91.97%. Comparing base (1a2d77b) to head (c9934ab).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main      #88      +/-   ##
==========================================
+ Coverage   91.80%   91.97%   +0.17%     
==========================================
  Files          21       21              
  Lines         805      810       +5     
==========================================
+ Hits          739      745       +6     
+ Misses         66       65       -1     

Flag	Coverage Δ
integration	60.24% <40.00%> (+0.12%)	⬆️
ollama_local	65.55% <40.00%> (-0.16%)	⬇️
slow-browser	55.92% <100.00%> (+1.14%)	⬆️
slow-other	71.11% <40.00%> (+0.30%)	⬆️
unit	65.67% <100.00%> (+3.69%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
src/microbots/MicroBot.py	100.00% <100.00%> (ø)

... and 1 file with indirect coverage changes

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.