Workflow: Debug with Breakpoints

This guide walks through the most common debugging workflow: setting a breakpoint, waiting for it to hit, inspecting variables, stepping through code, and evaluating expressions.

Scenario

You have a .NET application with a bug in a specific method. You know roughly where the problem is — you want to stop execution there, look at the state, and step through the code to find the issue.

Steps

1. Launch the application

"Launch /app/MyApp.dll and stop at the entry point"

The process starts and pauses at Main(), giving you a chance to set breakpoints before any code runs.

Tool call details

Request (debug_launch):

{
  "program": "/app/MyApp.dll",
  "stop_at_entry": true
}

2. Set a breakpoint

"Set a breakpoint at line 42 in UserService.cs"

The breakpoint is bound to the source location. When execution reaches this line, the process will pause.

Tool call details

Request (breakpoint_set):

{
  "file": "Services/UserService.cs",
  "line": 42
}

3. Continue and wait

"Continue execution and wait for the breakpoint"

The application runs until line 42 is hit.

Tool call details

Request (debug_continue):

{}

Then:

Request (breakpoint_wait):

{
  "timeout_ms": 30000
}

4. Inspect variables

"Show me the local variables"

See what values the variables have at the breakpoint.

Tool call details

Request (variables_get):

{
  "scope": "all"
}

Response:

{
  "variables": [
    { "name": "userId", "type": "string", "value": "\"abc123\"" },
    { "name": "user", "type": "User", "value": "null" }
  ]
}

5. Step through code

"Step over to the next line"

Move through the code line by line to observe how state changes.

Tool call details

Request (debug_step):

{
  "action": "over"
}

Use "action": "into" to enter a method call, or "action": "out" to finish the current method and return to the caller.

6. Evaluate expressions

"What is the value of items.Where(i => i.IsActive).Count()?"

Test hypotheses about the bug by evaluating arbitrary C# expressions.

Tool call details

Request (evaluate):

{
  "expression": "items.Where(i => i.IsActive).Count()"
}

7. Disconnect

"Stop debugging"

Tool call details

Request (debug_disconnect):

{
  "terminate": true
}

Summary

Step	Tool	Purpose
1	debug_launch	Start the app under debugger
2	breakpoint_set	Set a breakpoint at the suspected location
3	debug_continue + breakpoint_wait	Run until the breakpoint hits
4	variables_get	Inspect local variables
5	debug_step	Step through code line by line
6	evaluate	Test hypotheses with expressions
7	debug_disconnect	Clean up

Tips

• Use conditional breakpoints to avoid stopping on every call: "condition": "userId == null".
• Use breakpoint_set with function when you know the method name but not the line number.
• Inspect this to see the state of the current object: "scope": "this".
• Expand children with variables_get + "expand": "this._repository" to drill into nested objects.
• Use object_inspect for detailed information including field offsets, sizes, and memory addresses.