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name: sequential-thinking description: Structured reasoning tools for complex problem analysis with observation, hypothesis, analysis, and conclusion steps. Use when analyzing complex problems, debugging difficult issues, or making important decisions. allowed-tools: Read, Write mcp_tools:

• "think_step"
• "think_branch"
• "think_summarize"

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Sequential Thinking Skill

Version: 1.0.0 Purpose: Structured reasoning for complex problem analysis

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Triggers

Trigger	Examples
Analyze	"analyze problem", "think through", "問題分析"
Debug	"debug this", "investigate issue", "調査"
Decide	"help me decide", "evaluate options", "判断支援"
Reason	"reason about", "think step by step", "段階的に考える"

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Integrated MCP Tools

Tool	Purpose
think_step	Record a reasoning step
think_branch	Create alternative thinking branch
think_summarize	Summarize thinking session

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Step Types

Type	Purpose	Example
observation	Gather facts	"The error occurs at startup"
hypothesis	Form theory	"Configuration may be incorrect"
analysis	Evaluate	"Testing hypothesis against logs"
conclusion	Final result	"Root cause identified as X"
question	Open question	"What is the expected behavior?"

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Workflow: Problem Analysis

Phase 1: Observation

Step 1.1: Gather Facts

Use think_step with:
- thought: "Observed: [specific observation]"
- type: "observation"
- confidence: 0.9 (high certainty)

Step 1.2: Document Context

Multiple think_step calls for each fact:
- System state
- Error messages
- Recent changes
- User reports

Phase 2: Hypothesis Formation

Step 2.1: Form Hypotheses

Use think_step with:
- thought: "Hypothesis: [potential cause]"
- type: "hypothesis"
- confidence: 0.5 (initial guess)

Step 2.2: Alternative Hypotheses

Use think_branch to explore:
- Different root causes
- Alternative explanations
- Edge cases

Phase 3: Analysis

Step 3.1: Test Hypotheses

Use think_step with:
- thought: "Testing: [method and result]"
- type: "analysis"
- confidence: [adjusted based on evidence]

Step 3.2: Eliminate Options

Use analysis steps to:
- Confirm or refute each hypothesis
- Document evidence
- Adjust confidence levels

Phase 4: Conclusion

Step 4.1: Draw Conclusions

Use think_step with:
- thought: "Conclusion: [final determination]"
- type: "conclusion"
- confidence: 0.9 (based on evidence)

Step 4.2: Summarize Session

Use think_summarize with:
- sessionId: Current session
- includeAlternatives: true

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Branching Strategy

When to Branch

• Multiple valid hypotheses
• Need to explore alternatives
• Complex decision with trade-offs

Branch Usage

Use think_branch with:
- sessionId: Current session
- branchName: "alternative-approach"
- fromStep: Step number to branch from

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Confidence Levels

Level	Value	Meaning
Certain	0.9-1.0	Strong evidence, verified
Likely	0.7-0.9	Good evidence, probable
Possible	0.5-0.7	Some evidence, uncertain
Unlikely	0.3-0.5	Weak evidence
Doubtful	0.0-0.3	Little to no evidence

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Example Session

1. [observation] Error: "Connection refused" on port 5432
2. [observation] PostgreSQL service status: stopped
3. [hypothesis] Database service crashed
4. [hypothesis] Port conflict with another service
5. [analysis] Checking service logs... no crash, clean shutdown
6. [analysis] Checking port usage... no conflict
7. [conclusion] Service was manually stopped, needs restart

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Best Practices

✅ GOOD:

• Start with observations
• Form multiple hypotheses
• Document evidence for/against
• Update confidence as you learn

❌ BAD:

• Jump to conclusions
• Ignore contradicting evidence
• Single hypothesis bias
• Skip documentation

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Checklist

• Problem clearly stated
• Facts gathered (observations)
• Multiple hypotheses formed
• Evidence documented
• Alternatives explored (branches)
• Conclusion supported by evidence