Conciseness

Nearly every section restates arithmetic Claude already knows natively — 'result = 15 + 27 # Result: 42', the PEMDAS walkthrough ('Step 1: Parentheses: 10 + 5 = 15'), and tips like 'Use % for remainder (modulo)'. A version-dated footer ('Last Updated: October 25, 2025') adds time-sensitive metadata outside any deprecated section. This sits between anchors 1 and 2: the redundancy is document-wide rather than a few padded sections, but each section is brief and cleanly formatted rather than tutorial-prose padding.

Actionability

The Python snippets are executable and correct with expected outputs ('result = (10 + 5) * 2 ** 3 / 4', 'fahrenheit = (celsius * 9/5) + 32'), and the operations table gives concrete worked values. Minor gap: 'Division by zero returns error' is asserted but no handling is shown, keeping it short of copy-paste-ready full coverage.

Workflow Clarity

This is a simple single-task skill with no multi-step or fragile process, so the simple-skill exception applies: the single action (evaluate an arithmetic expression, optionally stepping through order of operations) is unambiguous, and sections progress cleanly from basic operations to complex expressions to unit conversions. No destructive or batch operations, so no validation cap applies.

Progressive Disclosure

The single-file body is well organized under clear headers ('## Quick Start', '## Supported Operations', '## Complex Expressions', '## Unit Conversions', '## Tips') with no dangling references, and nothing that belongs in a separate file is inlined. It falls short of anchor 5 because the ~100-line body exceeds the lean minimal-skill bar and the trailing 'Version / Last Updated / Example Type' footer adds navigational clutter.

Specificity

The description lists several concrete actions — 'basic arithmetic operations (addition, subtraction, multiplication, division)' — which matches 'several specific actions; minor gaps'. It is not 5 because modulo, exponent, and complex-expression support documented in the body are omitted, and not 3 because more than 1-2 actions are explicitly enumerated.

Completeness

Both parts are explicitly present: what ('Simple calculator for basic arithmetic operations (addition, subtraction, multiplication, division)') and when ('Use when performing calculations, converting units, or working with numbers'). It is not 5 because 'working with numbers' is generic, leaving the when-clause short of the fully concrete trigger phrases in the top anchor.

Trigger Term Quality

'performing calculations', 'converting units', and the four operation names are natural phrases users would say, giving good keyword coverage. It falls short of anchor 5 because common synonyms and variations such as 'math', 'compute', or 'calculate' are missing.

Distinctiveness Conflict Risk

The what-portion names a clear niche (a basic arithmetic calculator), but the trigger 'working with numbers' would match virtually any quantitative task — data analysis, spreadsheets, statistics — creating genuine overlap risk. This matches 'somewhat specific but could still overlap with similar skills' rather than 4, where overlap risk would be minor.