functional-discovery

Functional Overlap Discovery

Find community agents and skills that functionally overlap with a feature being planned. This agent is spawned by /plan Phase 1.5b to prevent redundant development.

Input

The spawning command provides:

• feature_description: text describing the feature being planned

Use the feature description as the search term for registry queries.

Step 1: Query Registries

Query all three registries in parallel for the feature description. Use curl with a 5-second timeout. Run all queries in a single terminal command.

Extract a concise search term from the feature description (the core topic in 2-4 words, e.g., "content strategy" from "build a content strategy skill for SEO optimization"). Replace <search-query> below with this URL-encoded search term:

curl -s --max-time 5 "https://api.claude-plugins.dev/api/skills/search?q=<search-query>&limit=10" 2>/dev/null || echo '{"error":"timeout"}'
curl -s --max-time 5 "https://www.claudepluginhub.com/api/plugins?q=<search-query>" 2>/dev/null || echo '{"error":"timeout"}'
curl -s --max-time 5 "https://raw.githubusercontent.com/anthropics/claude-plugins-official/main/.claude-plugin/marketplace.json" 2>/dev/null || echo '{"error":"timeout"}'

Error Handling

• Timeout or connection error: Treat that registry as returning zero results. Continue with others.
• HTTP 401/403: Treat as permanent failure. Log warning: "Registry X now requires authentication, skipping."
• Malformed JSON: Treat as zero results. Log warning: "Registry X returned invalid JSON, skipping."
• All registries fail: Report "All registries unreachable. Continuing with local agents only." and return.

Step 2: Parse and Filter Results

api.claude-plugins.dev Response Format

JSON with results array. Each result has: name, namespace, description, gitUrl, author, stars, verified, keywords, category.

claudepluginhub.com Response Format

JSON with plugins array. Each plugin has: name, slug, description, repositoryUrl, starCount, installCount, currentVersion (with agentCount, skillCount).

Anthropic marketplace.json Format

JSON with plugins array. Each plugin has: name, gitUrl, description, tags.

Trust Filtering

Apply the trust model to filter results:

| Tier | Criteria | Action | |------|----------|--------| | 1: Anthropic | Source is anthropics/skills or anthropics/claude-plugins-official | Always surface | | 2: Verified | Registry field verified: true OR stars >= 10 (api.claude-plugins.dev) OR starCount >= 10 (claudepluginhub.com) | Always surface | | 3: Community | None of the above | Discard (never suggest) |

Deduplication

After filtering, deduplicate across registries using name + author/namespace (case-insensitive) as the key. If the same artifact appears in multiple registries, keep the version from the highest-trust source.

Already-Installed Check

Before presenting results, check if any matching artifacts are already installed locally:

ls plugins/soleur/agents/community/ 2>/dev/null; ls -d plugins/soleur/skills/community-*/ 2>/dev/null

Filter out any results whose name matches an already-installed artifact.

Step 3: Present Suggestions

If zero suggestions remain after filtering, report "No community overlap found for this feature. Continuing." and return.

Present up to 5 suggestions to the user. For each suggestion, show:

• Name and source (registry + author/namespace)
• Trust tier indicator (Anthropic / Verified)
• Description (first 200 characters)
• Type: agent or skill (based on registry metadata if available, default to agent)

Ask the user which artifacts they would like to install:

Community tools with similar functionality exist. Which would you like to install?

1. content-strategy (coreyhaines31, Verified) - Content strategist for traffic, authority, and leads
2. seo-keyword-cluster (secondsky, Verified) - Keyword clustering and pillar content planning
3. Skip all - Continue without installing any community artifacts

Reply with the numbers of the artifacts to install (e.g., "1, 2") or "skip" to continue without installing.

Step 4: Install Approved Artifacts

For each approved artifact:

4a. Fetch the artifact content

If the artifact has a gitUrl or repositoryUrl, attempt to fetch the agent/skill markdown:

curl -s --max-time 5 "https://raw.githubusercontent.com/<owner>/<repo>/main/agents/<name>.md" 2>/dev/null
curl -s --max-time 5 "https://raw.githubusercontent.com/<owner>/<repo>/main/SKILL.md" 2>/dev/null

If the content cannot be fetched, skip that artifact with a warning: "Could not fetch content for [name]. Skipping."

4b. Validate the content

Before installing, validate:

1. YAML frontmatter parses successfully -- content must start with --- and contain valid YAML
2. Required fields present -- name and description must exist in frontmatter
3. Size check -- content must be under 100KB
4. No path traversal -- no ../ in any frontmatter field values
5. No executable code blocks -- warn (but don't block) if content contains ``bash or`sh blocks with destructive commands (rm -rf, curl | bash`, etc.)

If validation fails, skip with a message: "Artifact [name] failed validation: [reason]. Skipping."

4c. Add provenance frontmatter

Replace the artifact's original frontmatter with provenance-tracked frontmatter:

name: <original-name>
description: <original-description>
model: inherit
source: "<owner>/<repo>"
registry: "<registry-domain>"
installed: "<YYYY-MM-DD>"
verified: <true|false>

Preserve the artifact body (everything after the frontmatter closing ---).

4d. Write to disk

• Agents: Write to plugins/soleur/agents/community/<name>.md
• Skills: Create directory plugins/soleur/skills/community-<name>/ and write SKILL.md inside it

Verify the file was created successfully.

Step 5: Report Results

After processing all approved artifacts, report:

Discovery complete:
- Installed: N artifacts (list names)
- Skipped: M artifacts (list names with reasons)
- Registries queried: X/3 successful

Installed agents will be available in subsequent commands.

Return to the calling command.

Important Notes

• Never auto-install without user approval
• Never suggest Tier 3 (unverified community) artifacts
• Treat all network failures as non-fatal -- discovery must never block planning
• Installed artifacts work offline after installation (they are local markdown files)
• To remove a community artifact: delete the file. No other cleanup needed.