Silent Degradation Scanner

Detect code patterns where operations complete "successfully" but produce empty or useless results because preconditions are silently unmet.

When to Use This Skill

Use this skill when...	Use /code:review instead when...
A feature reports success but produces nothing	You need general code quality review
Scan/batch operations return 0 results silently	You want security or performance review
Users see green success banners for empty outcomes	You need SOLID principles assessment
Config-dependent features skip without warning	You want test coverage analysis
Multi-detector/multi-step operations silently skip steps	You need architecture review

Context

• Scan path: $ARGUMENTS (defaults to current directory if empty)
• Source files: !find . -maxdepth 1 \( -name "*.ts" -o -name "*.tsx" -o -name "*.js" -o -name "*.jsx" -o -name "*.py" -o -name "*.go" -o -name "*.rs" \) -type f
• Config patterns: !find . -maxdepth 1 \( -name ".env*" -o -name "config.*" -o -name "settings.*" \) -type f

Parameters

Parse from $ARGUMENTS:

• PATH: Directory or file to scan (defaults to .)
• --fix: Apply recommended fixes (add precondition checks, warning messages, status indicators)

Execution

Execute this silent degradation scan:

Step 1: Discover source files

Use Glob to find source files in the target path:

• **/*.ts, **/*.tsx, **/*.js, **/*.jsx for TypeScript/JavaScript
• **/*.py for Python
• **/*.go for Go
• **/*.rs for Rust

Exclude node_modules, dist, build, .git, vendor, __pycache__ directories.

Step 2: Scan for silent degradation patterns

Search each source file for these five pattern categories. Use Grep and Read to find matches.

Pattern 1: Silent skip on missing config

Code that checks for a config value and silently returns empty results when absent.

Indicators:

• if (!apiKey) or if not api_key: followed by return [] or return 0 or continue
• Environment variable checks that skip entire code paths without logging
• Feature flag checks that silently disable functionality
• process.env.X or os.environ.get() or os.Getenv() used in conditions that gate result-producing logic

Example of the problem:

// Silently returns nothing when Gemini isn't configured
if (!config.geminiApiKey) {
  return { suggestions: [] };  // No warning, no status
}

Pattern 2: Success message on zero results

Code that reports success regardless of whether meaningful work was performed.

Indicators:

• Success/completion messages that don't distinguish between "found results" and "found nothing because preconditions failed"
• Toast/notification/banner showing success with count === 0
• Log messages like "Completed" or "Done" or "Scan finished" when result set is empty
• HTTP 200 responses with empty arrays where the emptiness indicates a configuration problem, not genuinely zero matches

Example of the problem:

// Green banner whether it found 50 items or 0
toast.success(`Scan completed. Created ${results.length} suggestions.`);

Pattern 3: Multi-step operations with silent step skipping

Operations composed of multiple detectors/processors/steps where individual steps are skipped without surfacing this to the caller.

Indicators:

• Loop over detectors/analyzers/processors that catches errors and continues
• Skipped steps added to a list but not surfaced in the UI
• try/catch blocks that swallow errors and continue iteration
• Conditional execution of steps where skip reasons aren't propagated to the final result

Example of the problem:

for (const detector of detectors) {
  if (!detector.isAvailable()) {
    skipped.push(detector.name);  // Tracked but never shown
    continue;
  }
  results.push(...detector.run());
}
// skipped list exists but UX ignores it

Pattern 4: Missing precondition validation

Functions that require preconditions (data present, services configured, dependencies available) but don't validate or communicate them upfront.

Indicators:

• Functions that query a data source and produce results only if specific data shapes exist (e.g., "entities with embeddings", "orphan records", "records older than N days")
• No upfront check for whether the precondition is satisfiable
• No documentation or runtime message explaining what data/config is needed
• Database queries that naturally return empty when prerequisite data hasn't been set up

Example of the problem:

# Returns empty if no themes have embeddings - but doesn't check or warn
def find_similar_themes(threshold=0.85):
    themes = db.query(Theme).filter(Theme.embedding.isnot(None)).all()
    # If no embeddings exist, this silently returns []
    pairs = [(a, b) for a, b in combinations(themes, 2)
             if cosine_similarity(a.embedding, b.embedding) > threshold]
    return pairs

Pattern 5: Degraded mode without indication

Code that falls back to a degraded mode of operation (fewer features, reduced functionality) without any indication to the user that they're getting a partial experience.

Indicators:

• Feature availability checks that reduce functionality without notification
• Graceful degradation that's invisible to users
• Optional dependency checks that silently disable capabilities
• API version checks that fall back to limited functionality

Example of the problem:

// User has no idea they're getting a degraded scan
const detectors = [basicDetector];
if (geminiKey) detectors.push(aiDetector);      // silently omitted
if (hasEmbeddings) detectors.push(simDetector);  // silently omitted
return runDetectors(detectors);  // runs 1 of 3 with no indication

Step 3: Classify and report findings

For each finding, report:

Field	Content
File	file:line reference
Pattern	Which of the 5 patterns it matches
Severity	high (success message on empty), medium (silent skip), low (missing validation)
What happens	Describe the silent failure from the user's perspective
Preconditions	List what must be true for the code to produce results
Fix	Specific code change to surface the degradation

Severity guide:

• High: User sees explicit success messaging when nothing worked (Pattern 2, 3)
• Medium: Functionality silently disabled based on config/environment (Pattern 1, 5)
• Low: Missing upfront validation that would help users understand requirements (Pattern 4)

Step 4: Generate summary

Print a summary table:

Silent Degradation Scan: <path>

| Pattern                    | Findings | Severity |
|----------------------------|----------|----------|
| Silent config skip         | N        | medium   |
| Success on zero results    | N        | high     |
| Silent step skipping       | N        | high     |
| Missing precondition check | N        | low      |
| Degraded mode hidden       | N        | medium   |

Total: N findings across M files

Step 5: Apply fixes (if --fix)

If --fix is specified, apply these fixes for each finding:

1. Silent config skip: Add warning log before the early return
2. Success on zero results: Change success message to distinguish "nothing found" from "couldn't check" and surface skip reasons
3. Silent step skipping: Propagate skipped step information to the return value and surface in UI
4. Missing precondition check: Add upfront validation with descriptive error messages listing what's needed
5. Degraded mode hidden: Add status indicator showing which capabilities are active vs disabled

After applying fixes, list all changes made with file:line references.

Recommended Fixes Reference

Fix: Add precondition status panel

Before running multi-detector operations, check and display precondition status:

// Before
const results = await runScan();
toast.success(`Done. ${results.length} found.`);

// After
const status = checkPreconditions();
if (status.issues.length > 0) {
  showPreconditionPanel(status);  // "Gemini: not configured, Embeddings: 0 themes"
}
const results = await runScan();
toast.info(`Scan: ${results.active}/${results.total} detectors ran. ${results.length} found.`);

Fix: Distinguish "nothing found" from "couldn't check"

// Before
return { success: true, count: results.length };

// After
return {
  success: true,
  count: results.length,
  skipped: skippedDetectors,
  degraded: activeDetectors.length < totalDetectors,
  missingPreconditions: missingPrereqs,
};

Agentic Optimizations

Context	Command
Quick scan	/code:silent-degradation src/
Scan and fix	/code:silent-degradation src/ --fix
Specific file	/code:silent-degradation src/features/scanner.ts