Add Snowflake semantic view skill and contributing guidelines

CONTRIBUTING.md

@@ -103,6 +103,15 @@ You are an expert [domain/role] with deep knowledge in [specific areas].
 - [Best practices to follow]
 ```
 
+### Adding Skills
+
+Skills are self-contained folders in the `skills/` directory that include a `SKILL.md` file (with front matter) and optional bundled assets.
+
+1. **Create a new skill folder**: Run `npm run skill:create -- --name <skill-name> --description "<skill description>"`
+2. **Edit `SKILL.md`**: Ensure the `name` matches the folder name (lowercase with hyphens) and the `description` is clear and non-empty
+3. **Add optional assets**: Keep bundled assets reasonably sized (under 5MB each) and reference them from `SKILL.md`
+4. **Validate and update docs**: Run `npm run skill:validate` and then `npm run build` to update the generated README tables
+
 ### Adding Collections
 
 Collections group related prompts, instructions, and chat modes around specific themes or workflows, making it easier for users to discover and adopt comprehensive toolkits.

docs/README.skills.md

@@ -22,4 +22,5 @@ Skills differ from other primitives by supporting bundled assets (scripts, code
 
 | Name | Description | Bundled Assets |
 | ---- | ----------- | -------------- |
+| [snowflake-semanticview](../skills/snowflake-semanticview/SKILL.md) | Create, alter, and validate Snowflake semantic views using Snowflake CLI (snow). Use when asked to build or troubleshoot semantic views/semantic layer definitions with CREATE/ALTER SEMANTIC VIEW, to validate semantic-view DDL against Snowflake via CLI, or to guide Snowflake CLI installation and connection setup. | None |
 | [webapp-testing](../skills/webapp-testing/SKILL.md) | Toolkit for interacting with and testing local web applications using Playwright. Supports verifying frontend functionality, debugging UI behavior, capturing browser screenshots, and viewing browser logs. | `test-helper.js` |

skills/snowflake-semanticview/SKILL.md

@@ -0,0 +1,70 @@
+---
+name: snowflake-semanticview
+description: Create, alter, and validate Snowflake semantic views using Snowflake CLI (snow). Use when asked to build or troubleshoot semantic views/semantic layer definitions with CREATE/ALTER SEMANTIC VIEW, to validate semantic-view DDL against Snowflake via CLI, or to guide Snowflake CLI installation and connection setup.
+---
+
+# Snowflake Semantic Views
+
+## One-Time Setup
+
+- Verify Snowflake CLI installation by opening a new terminal and running `snow --help`.
+- If Snowflake CLI is missing or the user cannot install it, direct them to https://docs.snowflake.com/en/developer-guide/snowflake-cli/installation/installation.
+- Configure a Snowflake connection with `snow connection add` per https://docs.snowflake.com/en/developer-guide/snowflake-cli/connecting/configure-connections#add-a-connection.
+- Use the configured connection for all validation and execution steps.
+
+## Workflow For Each Semantic View Request
+
+1. Confirm the target database, schema, role, warehouse, and final semantic view name.
+2. Confirm the model follows a star schema (facts with conformed dimensions).
+3. Draft the semantic view DDL using the official syntax:
+   - https://docs.snowflake.com/en/sql-reference/sql/create-semantic-view
+4. Populate synonyms and comments for each dimension, fact, and metric:
+   - Read Snowflake table/view/column comments first (preferred source):
+     - https://docs.snowflake.com/en/sql-reference/sql/comment
+   - If comments or synonyms are missing, ask whether you can create them, whether the user wants to provide text, or whether you should draft suggestions for approval.
+5. Create a temporary validation name (for example, append `__tmp_validate`) while keeping the same database and schema.
+6. Always validate by sending the DDL to Snowflake via Snowflake CLI before finalizing:
+   - Use `snow sql` to execute the statement with the configured connection.
+   - If flags differ by version, check `snow sql --help` and use the connection option shown there.
+7. If validation fails, iterate on the DDL and re-run the validation step until it succeeds.
+8. Apply the final DDL (create or alter) using the real semantic view name.
+9. Clean up any temporary semantic view created during validation.
+
+## Synonyms And Comments (Required)
+
+- Use the semantic view syntax for synonyms and comments:
+
+```
+WITH SYNONYMS [ = ] ( 'synonym' [ , ... ] )
+COMMENT = 'comment_about_dim_fact_or_metric'
+```
+
+- Treat synonyms as informational only; do not use them to reference dimensions, facts, or metrics elsewhere.
+- Use Snowflake comments as the preferred and first source for synonyms and comments:
+  - https://docs.snowflake.com/en/sql-reference/sql/comment
+- If Snowflake comments are missing, ask whether you can create them, whether the user wants to provide text, or whether you should draft suggestions for approval.
+- Do not invent synonyms or comments without user approval.
+
+## Validation Pattern (Required)
+
+- Never skip validation. Always execute the DDL against Snowflake with Snowflake CLI before presenting it as final.
+- Prefer a temporary name for validation to avoid clobbering the real view.
+
+## Example CLI Validation (Template)
+
+```bash
+# Replace placeholders with real values.
+snow sql -q "<CREATE OR ALTER SEMANTIC VIEW ...>" --connection <connection_name>
+```
+
+If the CLI uses a different connection flag in your version, run:
+
+```bash
+snow sql --help
+```
+
+## Notes
+
+- Treat installation and connection setup as one-time steps, but confirm they are done before the first validation.
+- Keep the final semantic view definition identical to the validated temporary definition except for the name.
+- Do not omit synonyms or comments; consider them required for completeness even if optional in syntax.