---
name: explain
description: Explain and document MTHDS bundles. Use when user says "what does this pipeline do?", "explain this workflow", "explain this method", "walk me through this .mthds file", "describe the flow", "document this pipeline", "how does this work?", or wants to understand an existing MTHDS method bundle.
---

# Explain MTHDS bundles

Analyze and explain existing MTHDS method bundles in plain language.

## Process

**Prerequisite**: See [CLI Prerequisites](../shared/prerequisites.md)

### Step 1: Read the .mthds File

Read the entire bundle file to understand its structure.

### Step 2: Identify Components

List all components found in the bundle:
- **Domain**: the `[domain]` declaration
- **Concepts**: all `[concept.*]` blocks — note which are custom vs references to native concepts
- **Pipes**: all `[pipe.*]` blocks — identify the main pipe and sub-pipes
- **Main pipe**: declared in `[bundle]` section

### Step 3: Trace Execution Flow

Starting from the main pipe, trace the execution path:
1. For **PipeSequence**: follow the `steps` array in order
2. For **PipeBatch**: identify `batch_over` and `batch_as`, then the inner pipe
3. For **PipeParallel**: list all branches
4. For **PipeCondition**: map condition → pipe for each branch
5. For **PipeLLM / PipeExtract / PipeImgGen / PipeFunc**: these are leaf operations

### Step 4: Present Explanation

Structure the explanation as:

1. **Purpose**: one-sentence summary of what the method does
2. **Inputs**: list each input with its concept type and expected content
3. **Output**: the final output concept and what it contains
4. **Step-by-step flow**: walk through execution in order, explaining what each pipe does
5. **Key concepts**: explain any custom concepts defined in the bundle

### Step 5: Generate Flow Diagram

Create an ASCII diagram showing the execution flow:

```
[input_a, input_b]
        |
   main_sequence
   ├── step_one (PipeLLM) → intermediate_result
   └── step_two (PipeExtract) → final_output
```

Adapt the diagram style to the method structure (linear, branching, batched).

### Step 6: Optional — Validate

If the user wants to confirm the method is valid:
```bash
mthds-agent pipelex validate pipe <file>.mthds -L <bundle-dir>/
```

### Step 7: Optional — Visual Graph

For an interactive visual graph, suggest running the method with `/run` using real inputs:
```bash
mthds-agent pipelex run pipe <bundle-dir>/
```

This produces an interactive HTML visualization (`live_run.html`) next to the bundle alongside the execution results (graph is generated by default).

## Reference

- [CLI Prerequisites](../shared/prerequisites.md) — read at skill start to check CLI availability
- [Error Handling](../shared/error-handling.md) — read when CLI returns an error to determine recovery
- [MTHDS Agent Guide](../shared/mthds-agent-guide.md) — read for CLI command syntax or output format details
- [MTHDS Language Reference](../shared/mthds-reference.md) — read for concept definitions and syntax
- [Native Content Types](../shared/native-content-types.md) — read when explaining what data flows through pipes (e.g., what attributes Page or Image content carries)