Skill: Data Inspect

Purpose

Show the active dataset's schema — tables, columns, row counts, and relationships. Optionally drill into a specific table.

When to Use

Invoke as /data to see the full schema summary, or /data {table} to see column details for a specific table.

Instructions

Start here

Before doing ANYTHING else:

1. Read .knowledge/active.yaml to determine the active dataset name
2. If no active dataset exists, jump to Mode 3 (No Active Dataset)
3. Otherwise, read .knowledge/datasets/{active}/schema.md for schema information

Why this matters: Users often have multiple datasets connected. You MUST use the active one from the config file, never guess or use a different dataset.

Mode 1: /data (full schema overview)

When: User invokes /data or asks "what tables do I have?" / "show me the schema"

Steps:

1. ✅ Confirm you've already read .knowledge/active.yaml and schema.md (see above)
2. Extract from schema.md:
   • Dataset display name
   • Connection type and location
   • Table list with: name, row count, column count, primary key
3. Display in this condensed format:

Active Dataset: {display_name}
Connection: {type} ({database}.{schema} or file path)

Tables:
  users          ~50,000 rows   8 columns   user_id (PK)
  products           500 rows   7 columns   product_id (PK)
  events        ~6.5M rows     9 columns   event_id (PK)
  sessions       ~1.4M rows    8 columns   session_id (PK)
  orders        ~30-50K rows   6 columns   order_id (PK)
  order_items         — rows   4 columns   order_id + product_id (composite PK)

Use `/data {table}` for column details.

Format notes:

• Left-align table names
• Show approximate row counts (use ~ for estimates)
• Show column count
• Show primary key or composite key
• Keep it visually scannable — this is a quick reference, not exhaustive detail

Mode 2: /data {table} (table detail)

When: User invokes /data {table} or asks "what columns are in X?" / "show me the X table structure"

Steps:

1. ✅ Confirm you've already read .knowledge/active.yaml and schema.md (see above)
2. Find the section for the requested table in schema.md
3. If table doesn't exist: Jump to Mode 4 (Table Not Found)
4. If table exists: Display:
   • Table name and description
   • Row count
   • Full column listing: name, type, nullable, description
   • Primary key(s)
   • Foreign key relationships (both FROM this table and TO this table)
   • Any important notes about the table (grain, completeness, quirks)

Format example:

Active Dataset: {dataset_name}
Table: users

Description: User dimension table with demographics and signup info

Row count: ~25,000 rows
Primary Key: user_id

Columns:
  user_id          BIGINT       NOT NULL    Unique user identifier
  email            VARCHAR      NOT NULL    User email address
  signup_date      DATE         NULL        Date user first registered
  country          VARCHAR      NULL        User's country
  membership_tier  VARCHAR      NULL        Premium, Standard, Free

Relationships:
  ← orders.customer_id          (one user, many orders)
  ← events.user_id              (one user, many events)
  → memberships.user_id         (join for membership details)

Use `/data {another_table}` to inspect another table.

Mode 3: No Active Dataset

When: .knowledge/active.yaml has no active_dataset field OR the dataset directory doesn't exist

Display:

No active dataset configured.

To get started:
• Run `/connect-data` to connect a new dataset
• Run `/datasets` to see all available datasets
• Run `/switch-dataset {name}` to activate an existing dataset

Do NOT: Try to query databases, load CSV files, or guess which data source to use. Without an active dataset, halt and prompt the user.

Mode 4: Table Not Found

When: User requests /data {table} but the table doesn't exist in the active dataset's schema.md

Steps:

1. Confirm the table truly doesn't exist (check schema.md thoroughly, look for typos/case differences)
2. Display a helpful error message:

Table '{table}' not found in {dataset_name}.

Available tables:
  users, orders, products, events, sessions

Did you mean:
• /data {closest_match}
• /switch-dataset {other_dataset} if you're looking for different data
• /connect-data if the table should exist but isn't loaded

Use `/data` to see the full schema.

Do NOT: Query databases or try to load data from other sources. The skill reads from cached schema files only.

Anti-Patterns

1. Never query the database just to show schema — read from the cached schema.md file for speed. Schema files are pre-generated during dataset connection and profiling.
2. Never show the full schema.md raw — always format into the condensed table view. Users want quick scannable reference, not walls of markdown.
3. Read .knowledge/active.yaml first — users often have several datasets connected, and the active pointer is the only source of truth for which one to show.
4. Never query actual data — this skill shows structure only (schema, relationships). For data exploration, use the /explore skill or Data Explorer agent.
5. Never fabricate table information — if schema.md doesn't have row counts, say "~rows not profiled". If descriptions are missing, show what's available. Don't make up details.