source-evaluation

name	source-evaluation
description	This skill should be used when evaluating source credibility, deciding which search results to trust, choosing between search providers, detecting SEO spam or content farms, selecting domain-specific sources (academic, medical, legal, technical), evaluating software packages or libraries, comparing tools or technologies, assessing GitHub repo health, checking adoption metrics, or when research quality depends on retrieval quality. Covers the source credibility taxonomy (T1-T6 tiers), CRAAP framework adaptation, multi-provider search strategy, artifact evaluation framework (health/adoption/authority signals for packages, repos, APIs, standards, technologies), and source quality anti-patterns.
version	1.2.0

Source Evaluation

Source quality is the primary bottleneck in research agent pipelines. Research on deep research agent trajectories found that over 57% of source errors occur in early retrieval stages, where initial fabrication acts as the primary catalyst for cascading downstream errors (arXiv 2601.22984). A single bad source in the first retrieval round contaminates the entire research trajectory.

Source Credibility Tiers

Every source encountered during research falls into one of six tiers. Always prefer higher-tier sources and cite the tier when reporting findings.

Tier	Source Type	Examples	Trust Level
T1 — Primary	Peer-reviewed journals, official specs, primary datasets	Nature, Science, IEEE, IETF RFCs, W3C specs	Highest
T2 — Institutional	Government agencies, established research institutions	NIH, WHO, NIST, ACM Digital Library	High
T3 — Expert	Named expert blogs, conference proceedings, major tech engineering blogs	Anthropic blog, Google Research, NeurIPS/ICML papers	Moderate-High
T4 — Quality Editorial	Major publications with editorial review	MIT Technology Review, Ars Technica, The Verge	Moderate
T5 — Community	Well-moderated forums, high-reputation answers	Stack Overflow (high-score), GitHub discussions	Low-Moderate
T6 — Unverified	Content farms, SEO-optimized articles, anonymous posts, AI-generated content	Medium listicles, affiliate blogs, uncredited tutorials	Do not cite

Rule: Never cite T6 sources. Prefer T1-T3 for factual claims. Use T4-T5 for context and community consensus only.

The CRAAP Framework — Automated Signals

Adapted from the CRAAP framework (CSU Chico), five dimensions for evaluating sources:

Dimension	What to Check	Red Flags
Currency	Publication date, last-modified headers	No date visible, information predates major changes in the field
Relevance	Does it address the specific research question?	Tangential coverage, keyword-stuffed but shallow
Authority	Who published it? Credentials?	Anonymous author, no institutional affiliation, no citations
Accuracy	Are claims sourced? Can they be verified?	No inline citations, contradicts known facts, round numbers without source
Purpose	Is it informing, selling, or persuading?	High ad density, affiliate links, promotional language

Note: CRAAP evaluates surface features. Use it as an initial filter, not the sole credibility signal (Stanford research found reliance on CRAAP alone makes researchers susceptible to misinformation).

Multi-Provider Search Strategy

Different search providers excel in different domains. Route queries to the appropriate provider:

Provider	Best For	Limitations
WebSearch (general)	Broad topics, recent events, technical documentation	May surface SEO-optimized content
arXiv / Semantic Scholar	Academic ML/AI research, preprints	Not peer-reviewed, may be superseded
PubMed	Medical, biomedical, clinical research	Limited to biomedical domain
Official documentation	API specs, library usage, framework guides	May lag behind actual behavior
GitHub	Code examples, implementation patterns, issue discussions	Quality varies widely

Strategy: Start with domain-appropriate providers. Use general web search to fill gaps. Cross-reference findings across multiple providers when possible.

SEO Spam Detection

Red flags that indicate low-quality, SEO-optimized content:

• Listicle format with no depth ("Top 10 ways to...")
• Keyword stuffing — the search term appears unnaturally often
• No author attribution or author has no verifiable expertise
• High ad-to-content ratio
• Recycled/syndicated content appearing verbatim across multiple domains
• AI-generated markers — generic phrasing, lack of specific examples, overly smooth prose
• Affiliate links embedded throughout

When a source triggers 2+ red flags, discard it and search for a higher-quality alternative.

Artifact Evaluation

Research often involves evaluating non-content artifacts — packages, tools, technologies, standards, organizations. These require different signals than content sources. Every artifact has three signal dimensions:

Dimension	What It Measures	Key Question
Health	Is it alive and maintained?	When was the last meaningful activity?
Adoption	Does anyone actually use it?	What are the real usage numbers?
Authority	Who's behind it and are they credible?	Is this backed by a credible entity?

Artifact Types and Key Signals

Artifact Type	Health Signals	Adoption Signals	Authority Signals
Software packages	Last commit, release frequency, open issue response time	Downloads (npm weekly, PyPI monthly), dependents count	Maintainer reputation, organizational backing, license
GitHub repos	Commit frequency, PR merge time, stale issue ratio	Stars, forks, contributor count	Bus factor (>1 critical), corporate sponsor, notable users
APIs/Services	Uptime history, changelog frequency, deprecation notices	Customer logos, integration count, community size	Company funding, revenue stability, enterprise adoption
Standards/Specs	Last revision date, errata activity	Implementation count, conformance test suites	Standards body status (draft/proposed/standard), industry backing
Technologies	Release cadence, roadmap activity, CVE response time	Stack Overflow survey ranking, job postings, TIOBE/RedMonk index	Backing organization, governance model, ecosystem size
Architectural patterns	Recent case studies, active community discussion	Industry adoption breadth, conference talk frequency	Documented at-scale deployments, known failure case studies
People/Authors	Recent publication activity	Citation count, h-index, follower count	Institutional affiliation, industry role, peer recognition
Companies/Orgs	Recent funding, hiring activity, product releases	Revenue, customer count, market share	Investor quality, leadership track record, industry awards
Communities	Messages per week, new member rate	Member count, active member ratio	Moderation quality, notable members, signal-to-noise ratio
Datasets/Benchmarks	Last update, known issues addressed	Citation count, leaderboard participation	Creator credentials, methodology transparency, peer review
Claims/Statistics	Date of study, methodology recency	Citation count, replication status	Funding source, sample size, peer review, original source

Programmatic Stat Verification

When evaluating artifacts, use APIs for exact stats instead of search snippets:

Ecosystem	API Command	Returns
GitHub	gh api repos/{owner}/{name}	Stars, forks, license, language, last update, open issues
GitHub releases	gh api repos/{owner}/{name}/releases/latest	Latest version tag, release date
npm	curl api.npmjs.org/downloads/point/last-week/{pkg}	Exact weekly downloads
PyPI	curl pypistats.org/api/packages/{pkg}/recent	Recent download counts
crates.io	curl crates.io/api/v1/crates/{crate}	Downloads, version, recent downloads
RubyGems	curl rubygems.org/api/v1/gems/{gem}.json	Downloads, latest version
Maven	Search site:mvnrepository.com {artifact}	Usage stats page

These APIs return ground truth. Search snippets for these stats are unreliable.

Red Flags by Artifact Type

Software packages and repos:

• Last commit >6 months ago with open issues unanswered
• Fewer than 50 stars with no organizational backing
• Single maintainer (bus factor = 1) for critical dependency
• No tests, no CI, no changelog
• License incompatible with intended use

Technologies and standards:

• No major release in 12+ months
• Declining Stack Overflow activity trend
• Abandoned by original backing organization
• No conformance test suite (for standards)

Claims and statistics:

• No original source cited (circular citation)
• Study funded by party with commercial interest in the outcome
• Sample size <100 for quantitative claims
• No methodology description

General rule: When an artifact triggers 2+ red flags, flag it explicitly in the research output. Do not recommend it without noting the risks.

For detailed per-artifact-type evaluation guides and how to check each signal programmatically, consult references/artifact-signals.md.

Retrieval Best Practices

1. Front-load quality — The first retrieval round disproportionately determines research quality due to the saturation bottleneck (agents fixate on early results). Start with high-authority sources.
2. Search iteratively — Refine search queries based on initial results. First search identifies terminology; second search uses domain-specific terms.
3. Diversify sources — Do not rely on a single provider or a single source for any claim. Cross-reference across independent sources.
4. Verify fetched content — After WebFetch, scan the content for authority signals (author credentials, citations, publication venue) before incorporating.
5. Track provenance — Record which source produced which claim. This metadata is essential for citation and for tracing errors.

Retrieval Anti-Patterns

Anti-Pattern	Problem	Fix
Single-provider dependency	All searches go through one provider	Route by domain; use multiple providers
First-result trust	Accepting the top search result without evaluation	Evaluate credibility tier before incorporating
Equal credibility	Treating a blog post the same as a journal paper	Apply tier system; weight higher-tier sources
Ignoring retrieval failures	Silent fallback when search returns nothing useful	Log the gap; try alternative queries or providers
Breadth without depth	Fetching 20 URLs but reading none carefully	Fetch fewer sources; read each thoroughly

Reference Files

For detailed provider comparison, domain-specific source guides, and artifact evaluation:

• references/provider-comparison.md — Detailed comparison of search providers with API specifics, rate limits, and optimal use cases
• references/artifact-signals.md — Per-artifact-type evaluation guides with health/adoption/authority thresholds, how to check each signal, and the quick evaluation checklist