Feature Discovery Skill

This skill provides dynamic feature documentation discovery for the Project Amp codebase. It enables lazy loading of feature context based on user queries.

When to Use This Skill

Use this skill when:

•User asks about a feature or functionality
•User wants to understand how something works
•User asks "what is X?" or "how does X work?"
•User references a component and wants context
•Before implementing features to understand existing functionality
•User asks about Project Amp capabilities

How Feature Discovery Works

Feature documentation uses lazy loading via YAML frontmatter:

•Query frontmatter: Extract all feature metadata using discovery command
•Match user query: Compare query against feature names, descriptions, and components
•Load relevant docs: Read only the matched feature docs

Available Commands

Discovery Command

The discovery command extracts all feature frontmatter for lazy loading.

Primary Method: Use the Grep tool with multiline mode:

•Pattern: ^---\n[\s\S]*?\n---
•Path: docs/features/
•Glob: *.md
•multiline: true
•output_mode: content

Extracts YAML frontmatter from all feature docs. Returns feature metadata for matching.

Fallback: Bash command (if Grep tool is unavailable):

bash

grep -Pzo '(?s)^---\n.*?\n---' docs/features/*.md 2>/dev/null | tr '\0' '\n'

Cross-platform alternative (macOS compatible):

bash

awk '/^---$/{p=!p; print; next} p' docs/features/*.md

Use this when: You need to see all available features and their descriptions.

Read Specific Feature Doc

Use the Read tool to load docs/features/<feature-name>.md.

Use this when: You've identified which feature doc is relevant to the user's query.

Discovery Workflow

Step 1: Extract All Feature Metadata

Run the discovery command (Grep tool primary, bash fallback).

Step 2: Match User Query

Compare the user's query against:

•name field (exact or partial match)
•description field (semantic match)
•components field (crate/module names)

Step 3: Load Matched Features

Read the full content of matched feature docs using the Read tool.

Query Matching Guidelines

Exact Matches

•User asks about "admin API" -> match name: "admin-api"
•User mentions "JSONL queries" -> match name: "jsonl-sql-batch-query"
•User references "metadata database" -> match components: "crate:metadata-db"

Semantic Matches

•User asks "how do I query data?" -> match descriptions containing "query"
•User asks "what are UDFs?" -> match descriptions containing "user-defined functions"
•User asks "how does extraction work?" -> match descriptions containing "extract"

Component Matches

•User working in crates/services/worker -> match components: "service:worker"
•User editing admin-api handlers -> match components: "crate:admin-api"
•User modifying server code -> match components: "service:server"

Important Guidelines

Pre-approved Commands

These tools/commands can run without user permission:

•Discovery command (Grep tool or bash fallback) on docs/features/ - Safe, read-only
•Reading feature docs via Read tool - Safe, read-only

When to Load Multiple Features

Load multiple feature docs when:

•User query matches multiple features
•Feature has dependencies on other features (check Related Features section)
•User is working on integration between components

When NOT to Use This Skill

•User asks about code patterns -> Use /code-pattern-discovery skill
•User needs to run commands -> Use appropriate /code-* skill
•User is doing simple file edits -> No discovery needed
•User asks about implementation details -> Use /code-pattern-discovery skill
•User asks if implementation matches docs -> Use /feature-validate

Example Workflows

Example 1: User Asks About a Feature

Query: "How do I execute SQL queries against datasets?"

•Run the discovery command to extract all feature metadata
•Match "sql" and "query" against feature descriptions
•Find match: jsonl-sql-batch-query with description "Execute one-shot SQL batch queries..."
•Load docs/features/jsonl-sql-batch-query.md
•Provide summary from loaded doc

Example 2: User Working on Multiple Components

Query: "I need to understand how the server handles requests"

•Run the discovery command to extract feature metadata
•Match features with components: "service:server"
•Load all matched feature docs
•Explain the interaction based on loaded context

Example 3: Before Implementing a Feature

Query: "I want to add a new query endpoint"

•Run the discovery command to extract feature metadata
•Match existing query-related features
•Load relevant docs to understand existing patterns
•Identify related features for reference

Example 4: No Match Found

Query: "How does feature X work?" (where X doesn't exist)

•Run the discovery command to extract feature metadata
•No matches found in frontmatter
•Inform user no feature doc exists for X
•Suggest using /code-pattern-discovery or asking for clarification

Common Mistakes to Avoid

Anti-patterns

Mistake	Why It's Wrong	Do This Instead
Hardcode feature lists	Lists become stale	Always use dynamic discovery
Load all feature docs	Bloats context	Use lazy loading via frontmatter
Skip discovery step	Miss relevant features	Match query to metadata first
Guess feature names	May not exist	Run discovery command to verify

Best Practices

•Use Grep tool first to see available features
•Match user query to feature metadata before loading full docs
•Load only relevant features to avoid context bloat
•Follow cross-references in "Related Features" sections
•Check component field for crate-specific features

Next Steps

After discovering relevant features:

•Understand context - Read loaded feature docs thoroughly
•Check patterns - Use /code-pattern-discovery for implementation details
•Identify related features - Follow cross-references in Related Features
•Begin implementation - Use appropriate /code-* skills for development