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nosql-expert

Expert guidance for distributed NoSQL databases (Cassandra, DynamoDB). Focuses on mental models, query-first modeling, single-table design, and avoiding hot partitions in high-scale systems.

Quality

72%

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tessl review fix ./skills/nosql-expert/SKILL.md
SKILL.md
Quality
Evals
Security

Quality

Content

67%Weight 40%Scale 1-5

Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.

The content is a well-structured, largely actionable reference for Cassandra/DynamoDB design, with concrete examples, a clear design process, and an expert checklist serving as validation. Weaknesses are moderate redundancy in restating the query-first principle and generic framing that could be trimmed, plus no complete executable query examples.

Suggestions

State the query-first principle once (keep the Golden Rule or the comparison table, not both plus the Overview paragraph) and trim generic statements like 'Data is distributed across physical nodes based on the Partition Key' to improve token efficiency.

Add one or two complete executable examples (e.g., a CQL `CREATE TABLE` with partition/clustering keys and the matching `SELECT`, or a DynamoDB GetItem on `USER#123`) so the access-pattern guidance is copy-paste ready.

Consider splitting the engine-specific sections ('Apache Cassandra / ScyllaDB' and 'AWS DynamoDB') into one-level-deep reference files (e.g., references/cassandra.md, references/dynamodb.md) to improve progressive disclosure as the skill grows.

DimensionReasoningScore

Conciseness

The body is mostly tight (tables, checklists, short bullets), but the core query-first principle is stated three times ('you model your queries first', the SQL-vs-NoSQL table row 'Model **Queries** (Access Patterns)', and 'The Golden Rule' blockquote), and the Overview restates the description. Some entries also restate well-known basics ('Data is distributed across physical nodes based on the Partition Key'), so it could be tightened rather than being uniformly lean. Not 2 — no heavily padded or long-winded sections; not 4 — the repetition and generic framing exceed 'minor instances'.

3 / 5

Actionability

Concrete, specific guidance throughout: the 3-step query-first process ('List all Entities... List all Access Patterns... Design Table(s)'), a worked single-table example with real key values (`USER#123` / `ORDER#998`, `Query: PK="USER#123"`), concrete key structure `((Partition Key), Clustering Columns)`, and a specific threshold with a fix ('If > 10GB... shard the partition, e.g., `USER#123#2024-01`'). Minor gaps: no complete CQL/PartiQL or DDL examples for the access patterns, keeping it just short of fully executable guidance.

4 / 5

Workflow Clarity

The query-first process (entities → access patterns → table design) is a clear numbered sequence, and the 'Expert Checklist' provides explicit pre-finalization checkpoints (access pattern coverage, cardinality check, split partition risk, consistency requirement). Not 5: the checklist is a validation gate but there is no validate/fix/retry feedback loop, and the remaining sections are reference material without sequencing. Not 3: checkpoints are explicit, not merely implicit. This is a design skill, so the destructive/batch validation cap does not apply.

4 / 5

Progressive Disclosure

The body (~105 lines) is a single well-organized file with clear section headers (Overview, When to Use, Core Design Patterns, Specific Guidance per engine, Expert Checklist, Anti-Patterns) and no nested or broken references — the bundle has no external files, so nothing is buried. Minor gap: at this length, the engine-specific guidance (Cassandra/ScyllaDB vs DynamoDB) could be split into one-level-deep reference files, which keeps it at 4 rather than 5.

4 / 5

Total

15

/

20

Passed

Description

66%Weight 40%Scale 1-5

Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.

The description is specific and distinct, naming concrete focus areas (query-first modeling, single-table design, hot partitions) and specific technologies (Cassandra, DynamoDB). Its main weakness is the absence of any 'Use when...' trigger clause, which caps completeness, and it omits some natural trigger terms like ScyllaDB and schema design.

Suggestions

Add an explicit trigger clause, e.g. 'Use when designing schemas for Cassandra, ScyllaDB, or DynamoDB, when troubleshooting hot partitions or high latency, or when evaluating database-per-service patterns.'

Include the natural synonyms users would actually say — 'ScyllaDB', 'data modeling', 'partition key design', 'NoSQL schema design' — to improve trigger term coverage.

Replace the abstract framing 'Expert guidance ... mental models' with concrete action verbs (e.g. 'Design query-first schemas, apply single-table patterns, avoid hot partitions') to strengthen specificity.

DimensionReasoningScore

Specificity

Quotes 'Focuses on mental models, query-first modeling, single-table design, and avoiding hot partitions' — several specific, concrete capabilities are named within the distributed NoSQL domain, though 'Expert guidance' and 'mental models' are somewhat abstract framing. Not 5 because it describes focus areas rather than a comprehensive list of concrete actions; not 3 because more than 1-2 concrete capabilities are explicitly listed.

4 / 5

Completeness

The 'what' is clear ('Expert guidance for distributed NoSQL databases... Focuses on mental models, query-first modeling, single-table design, and avoiding hot partitions') but there is no 'Use when...' clause or equivalent explicit trigger guidance — 'high-scale systems' only weakly implies the 'when'. Per the guideline, a missing 'Use when' clause caps completeness at 3: clear 'what', 'when' absent/weakly implied.

3 / 5

Trigger Term Quality

Natural terms present: 'distributed NoSQL databases', 'Cassandra', 'DynamoDB', 'single-table design', 'hot partitions', 'high-scale systems'. A few natural terms users would say are missing: 'ScyllaDB', 'schema/data modeling', 'partition key', 'DynamoDB table design'. Good coverage but not comprehensive synonym coverage, so 4 rather than 5; well above generic one-keyword level (2) or missing-variation level (3).

4 / 5

Distinctiveness Conflict Risk

The parenthetical '(Cassandra, DynamoDB)' plus 'single-table design' and 'hot partitions' carves a clear niche distinct from SQL or document-store skills. Minor overlap risk remains with broader database/data-modeling skills or other NoSQL engines (e.g., MongoDB) since 'distributed NoSQL databases' is stated generally and ScyllaDB is not named here. Mostly distinct with minor overlap, so 4 rather than 5.

4 / 5

Total

15

/

20

Passed

Validation

93%

Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.

Validation — 15 / 16 Passed

Validation for skill structure

CriteriaDescriptionResult

frontmatter_unknown_keys

Unknown frontmatter key(s) found; consider removing or moving to metadata

Warning

Total

15

/

16

Passed

Repository

administrakt0r/AI-Agents-Safe-Coding-Skills

Path

skills/nosql-expert/SKILL.md

Reviewed

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