matthull Research Skill
Conduct rigorous research with parallel subagents, producing documents with proper footnote citations that maintain a chain of evidence across all derivative documents.
Core Principle: Chain of Evidence
Every claim traces back to a primary source.
Research findings are only as valuable as their verifiability. When creating research documents or any downstream documents derived from research:
- Primary research documents must cite original sources with footnotes
- Downstream documents (summaries, decisions, plans) must preserve footnote references to the original sources, not to the research document itself
- The chain is unbroken - a reader can trace any claim in any document back to a verifiable primary source
Why This Matters
Without chain of evidence:
- Claims become "telephone game" assertions
- Verification becomes impossible over time
- Decisions rest on unverifiable foundations
With chain of evidence:
- Any claim can be independently verified
- Documents remain useful even as context is lost
- Decisions have clear supporting evidence
Phase 1: Query Classification
Before researching, classify the query to determine the appropriate strategy.
Query Types
1. LIBRARY/API DOCUMENTATION (Context7 preferred)
- Questions about library APIs, framework usage, package documentation
- Examples: "How do I use React hooks?", "PowerSync API for offline sync"
- Strategy: Use Context7 first, fall back to web search if insufficient
2. BREADTH-FIRST (Wide exploration)
- Multiple independent aspects, survey questions, comparisons
- Examples: "Compare managed Postgres providers", "Evaluate cloud providers"
- Strategy: 5-10 parallel subagents, each exploring different aspects
3. DEPTH-FIRST (Deep investigation)
- Single topic requiring thorough understanding
- Examples: "How does transformer architecture work?", "Postgres logical replication limits"
- Strategy: 2-4 subagents with overlapping but complementary angles
4. SIMPLE FACTUAL (Quick lookup)
- Single fact, recent event, specific data point
- Examples: "When was GPT-4 released?", "Current CEO of Microsoft"
- Strategy: 1-2 subagents for verification
Phase 2: Parallel Research Execution
Spawn appropriate research subagents in a single message for true parallelization.
Task Prompts Must Include Mode Indicator
Start each task prompt with a trigger phrase:
| Mode | Trigger Phrases | Effort |
|---|---|---|
| Quick Verification | "Quick check:", "Verify:", "Confirm:" | 3-5 searches |
| Focused Investigation | "Investigate:", "Explore:", "Find details about:" | 5-10 searches |
| Deep Research | "Deep dive:", "Comprehensive:", "Thorough research:" | 10-15 searches |
Example Parallel Launch
Task(description="RDS research",
prompt="Investigate: Amazon RDS for PostgreSQL - backup retention, SLA terms, maintenance windows, and major-version upgrade path",
subagent_type="research-expert")
Task(description="Cloud SQL research",
prompt="Investigate: Google Cloud SQL for PostgreSQL - backup retention, SLA terms, maintenance windows, and major-version upgrade path",
subagent_type="research-expert")
Task(description="PG version policy",
prompt="Deep dive: PostgreSQL community major-version support policy and end-of-life dates",
subagent_type="research-expert")
Subagent Output Pattern
Each subagent writes full report to /tmp/research_[timestamp]_[topic].md and returns:
- File path to the full report
- Brief 2-3 sentence summary
- Key topics covered
- Number of sources found
Phase 3: Synthesis with Footnotes
Footnote Format (Required)
Follow the citation format defined in the /citations skill. Key points summarized below for quick reference.
Every significant claim must have a footnote. Use this format:
Inline reference:
Amazon RDS publishes a 99.95% Multi-AZ availability SLA[^rds-sla] and retains automated backups for up to 35 days[^rds-backup].
Footnote definition (at document end):
[^rds-sla]: Amazon RDS Service Level Agreement. 99.95% monthly uptime commitment for Multi-AZ deployments. [View Source](https://aws.amazon.com/rds/sla/) (accessed 2026-01-15)
[^rds-backup]: Amazon RDS User Guide, "Working with backups". Automated backup retention configurable from 0 to 35 days. [View Source](https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_WorkingWithAutomatedBackups.html) (accessed 2026-01-15)
Footnote Naming Convention
Use short, descriptive slugs:
[^rds-backup]- RDS backup retention[^cloudsql-pricing]- Cloud SQL pricing tiers[^pg-eol]- PostgreSQL end-of-life policy
Pattern: [^org-topic] or [^topic-subtopic]
Footnote Components
Each footnote must include:
- Source name/organization - Who published this
- Document/page title - What the source is (in quotes if a title)
- Key claim - What the source says (brief paraphrase)
- Link - Clickable link with descriptive text
[View Source](URL) - Access date - When accessed
(accessed YYYY-MM-DD)
Evidence Quality Tiers
Flag source quality when relevant:
| Tier | Source Type | Reliability |
|---|---|---|
| 1 | Official docs, primary sources, peer-reviewed | Authoritative |
| 2 | Official examples, starter repos, official blogs | High |
| 3 | Verified community patterns (multiple sources agree) | Moderate |
| 4 | Single blog post, forum answer, outdated content | Low (flag uncertainty) |
Phase 4: Chain of Evidence in Downstream Documents
Critical Rule: When creating documents derived from research, preserve footnote references to original sources.
Anti-pattern (Broken Chain)
## Decision Document
RDS retains automated backups for up to 35 days (see research-findings.md).
This breaks the chain - a reader cannot verify the claim without finding the research document.
Correct Pattern (Preserved Chain)
## Decision Document
RDS retains automated backups for up to 35 days[^rds-backup].
---
## Footnotes
[^rds-backup]: Amazon RDS User Guide, "Working with backups". Automated backup retention configurable from 0 to 35 days. [View Source](https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_WorkingWithAutomatedBackups.html) (accessed 2026-01-15)
The footnote travels with the claim. Any document, anywhere, can be verified.
Propagation Rules
- Copy footnotes with claims - When moving a claim to a new document, move its footnote too
- Consolidate duplicate footnotes - If multiple claims use the same source, use one footnote
- Never cite research docs as sources - Cite the primary source the research doc cited
- Update access dates - If re-verifying a source, update the access date
Research Report Structure
The synthesized report (written to file) should include:
# Research Report: [Topic]
**Date:** [YYYY-MM-DD]
**Status:** [Draft/Final]
## Executive Summary
[3-5 paragraph overview synthesizing all findings]
## Key Findings
1. **[Finding 1]** - Description with source attribution[^source1]
2. **[Finding 2]** - Description with source attribution[^source2]
3. **[Finding 3]** - Description with source attribution[^source3]
## Detailed Analysis
### [Theme 1]
[Comprehensive analysis with inline footnote citations]
### [Theme 2]
[Comprehensive analysis with inline footnote citations]
## Unknowns / Follow-Up Required
- [ ] [Question that couldn't be answered]
- [ ] [Verification needed for uncertain claim]
## Footnotes
[^source1]: [Full footnote definition]
[^source2]: [Full footnote definition]
...
## Document History
- **[Date]:** Initial research
- **[Date]:** Added [specific updates]
Handling Uncertainty
Flag Gaps Explicitly
When evidence is incomplete:
**Note:** No authoritative source found for exact per-region pricing. Tiered pricing is documented[^rds-pricing] but the specific rates vary by region.
Uncertainty Markers
[UNCERTAIN - no authoritative source]- Claim based on inference[CONFLICTING]- Sources disagree (present both positions)[SINGLE SOURCE]- Claim relies on only one reference[OUTDATED - verify current status]- Source is >2 years old on fast-moving topic
Execution Checklist
Before finalizing any research document:
- Every significant claim has a footnote
- Footnotes include source, title, brief description, link, and access date
- Uncertainty is flagged explicitly
- Sources are appropriate tier for the claim's importance
- Downstream documents preserve footnotes (don't cite research docs)
Example: Good Footnote Practices
From documents/research/managed-postgres-comparison.md:
Inline:
Both RDS and Cloud SQL drop support for a PostgreSQL major version once the community marks it end-of-life.[^pg-eol]
Definition:
[^pg-eol]: PostgreSQL Global Development Group, "Versioning Policy" (accessed 2026-01-15). Each major version is supported for five years after its initial release. [View Source](https://www.postgresql.org/support/versioning/)
This footnote includes:
- Source organization (PostgreSQL Global Development Group)
- Document title ("Versioning Policy")
- Date (accessed 2026-01-15)
- What it says (five years of support per major version)
- Clickable link with descriptive text