Sequential Thinking — Structured Reasoning
You are an expert at using the Sequential Thinking MCP server for structured, revisable multi-step reasoning. This tool helps decompose complex problems into numbered thoughts with support for revision and branching.
Critical: These Are Direct Tool Calls
MCP tools are direct tool calls — exactly like Read, Grep, or Bash. They are NOT CLI commands.
CORRECT — call the tool directly:
Tool: mcp__sequential-thinking__sequentialthinking
Parameters: {
"thought": "First, let me identify the possible causes of the RLS policy failure...",
"thoughtNumber": 1,
"totalThoughts": 5,
"nextThoughtNeeded": true
}WRONG — do NOT shell out:
Bash: claude mcp call sequential-thinking sequentialthinking ... # This does not workThe single tool uses the mcp__sequential-thinking__sequentialthinking prefix.
When to Use (and When NOT to)
| Use Sequential Thinking | Do NOT Use |
|---|---|
| Bug with 3+ possible causes needing elimination | Simple typo or obvious error |
| Architectural decision with competing trade-offs | Straightforward implementation |
| Multi-factor analysis where factors interact | Single-factor decision |
| Root cause analysis requiring hypothesis testing | Error with clear stack trace |
| Problems where early assumptions might be wrong | Problems with known solutions |
Rule of thumb: If you can solve it in your head in one step, don't use this tool. If you need to "think out loud" with potential backtracking, use it.
Tool Parameters
| Parameter | Type | Required | Purpose |
|---|---|---|---|
thought | string | Yes | The content of this reasoning step |
thoughtNumber | number | Yes | Current step number (1-indexed) |
totalThoughts | number | Yes | Estimated total steps (can adjust) |
nextThoughtNeeded | boolean | Yes | true to continue, false when done |
isRevision | boolean | No | true if revising an earlier thought |
revisesThought | number | No | Which thought number is being revised |
branchFromThought | number | No | Start an alternative path from this thought |
branchId | string | No | Label for the branch (e.g., "alternative-approach") |
needsMoreThoughts | boolean | No | true to extend beyond initial estimate |
Workflow 1: Problem Decomposition
Trigger: Complex bug with multiple possible causes, or a decision requiring systematic analysis.
Steps
- Frame the problem (thought 1):
sequentialthinking({thought: "The timesheet approval is failing silently. Three possible causes: (1) RLS policy blocking the update, (2) has_permission() returning false, (3) trigger rejecting the state transition.", thoughtNumber: 1, totalThoughts: 5, nextThoughtNeeded: true}) - Analyze each hypothesis (thoughts 2-4):
sequentialthinking({thought: "Testing hypothesis 1: The RLS policy for timesheets requires has_role_on_account(account_id) AND the user must be manager_or_above. Let me check if the user has the right role...", thoughtNumber: 2, totalThoughts: 5, nextThoughtNeeded: true}) - Revise if earlier thinking was wrong (optional):
sequentialthinking({thought: "Revising thought 2: Actually, the new permission system uses has_permission() not has_role_on_account(). The RLS policy might be using the old function.", thoughtNumber: 4, totalThoughts: 6, nextThoughtNeeded: true, isRevision: true, revisesThought: 2, needsMoreThoughts: true}) - Conclude (final thought):
sequentialthinking({thought: "Root cause identified: The RLS policy uses has_role_on_account() which checks system roles, but the user only has a custom role assigned. Need to update the policy to use has_permission() instead.", thoughtNumber: 6, totalThoughts: 6, nextThoughtNeeded: false})
Workflow 2: Architectural Decision
Trigger: User asks "should we use X or Y?", "what's the best approach for Z?", or there are multiple valid implementation strategies.
Steps
- Define the decision criteria (thought 1)
- Evaluate option A against criteria (thought 2)
- Evaluate option B against criteria (thought 3)
- Branch if a hybrid approach emerges (optional):
sequentialthinking({thought: "What if we combine the service pattern from option A with the caching strategy from option B?", thoughtNumber: 4, totalThoughts: 6, nextThoughtNeeded: true, branchFromThought: 3, branchId: "hybrid-approach"}) - Recommend with trade-off summary (final thought)
Workflow 3: Multi-Factor Analysis
Trigger: Complex decision involving performance, security, maintainability, and other competing concerns.
Pattern
- Thought 1: List all factors and their relative importance
- Thoughts 2-N: Analyze each factor independently
- Revision thoughts: Update earlier analysis as new interactions between factors emerge
- Final thought: Synthesize into a recommendation with explicit trade-offs
Key Patterns
- Start with an estimate of
totalThoughts— 5 is a good default. Adjust withneedsMoreThoughts: trueif you need more. - Use
isRevision: truewhen you realize an earlier thought was wrong or incomplete — don't just silently change direction. - Use
branchFromThoughtto explore "what if?" alternatives without abandoning the main analysis. - Set
nextThoughtNeeded: falseonly when you have a clear conclusion — not just when you run out of thoughts. - Each thought should be substantive — avoid placeholder thoughts like "Let me think about this more."
Troubleshooting
Reasoning Chain Gets Too Long
If you're past thought 10 and still going:
- Set
nextThoughtNeeded: falseand summarize what you know so far - The problem might need breaking into sub-problems — solve each separately
- Consider if you actually need this tool or if the problem is simpler than you thought
Losing Track of the Thread
Use isRevision and revisesThought to explicitly connect corrections to earlier thoughts. This helps maintain a coherent chain rather than just appending unconnected thoughts.
Tool Seems Unnecessary for This Problem
If you find yourself forcing sequential thinking on a straightforward problem, just stop and solve it directly. This tool adds value for genuinely complex reasoning — not for every problem.